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Components:
Metformin Hydrochloride, Pioglitazone Hydrochloride
Method of action:
Drugs Used In Diabets
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Medically reviewed by Militian Inessa Mesropovna, PharmD. Last updated on 2019.11.21

Name of the medicinal product

Actoplus MET, Actoplus MET XR

Qualitative and quantitative composition

Dosage Forms And Strengths

  • 15 mg/500 mg tablets: White to off-white, oblong, film-coated tablets debossed with “4833M” on one side and “15/500” on the other
  • 15 mg/850 mg tablets: White to off-white, oblong, film-coated tablets debossed with “4833M” on one side and “15/850” on the other

Storage And Handling

ACTOPLUS MET is available in 15 mg pioglitazone (as the base)/500 mg metformin hydrochloride and 15 mg pioglitazone (as the base)/850 mg metformin hydrochloride tablets as follows:

15 mg/500 mg tablet: white to off-white, oblong, film-coated tablet with “4833M” on one side and “15/500” on the other, available in:

Bottles of 60 NDC 64764-155-60
Bottles of 180 NDC 64764-155-18

15 mg/850 mg tablet: white to off-white, oblong, film-coated tablet with “4833M” on one side and “15/850” on the other, available in:

Bottles of 60 NDC 64764-158-60
Bottles of 180 NDC 64764-158-18

Storage

Store at 25°C (77°F); excursions permitted to 15°-30°C (59°-86°F). Keep container tightly closed, and protect from moisture and humidity.

Distributed by: Takeda Pharmaceuticals America, Inc., Deerfield, IL 60015. Revised: Jul 2014

Therapeutic indications

ACTOPLUS MET is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus when treatment with both pioglitazone and metformin is appropriate.

Important Limitations Of Use

Pioglitazone exerts its antihyperglycemic effect only in the presence of endogenous insulin. ACTOPLUS MET should not be used to treat type 1 diabetes or diabetic ketoacidosis, as it would not be effective in these settings.

Use caution in patients with liver disease.

Dosage (Posology) and method of administration

Recommendations For All Patients

ACTOPLUS MET should be taken with meals to reduce the gastrointestinal side effects associated with metformin.

If therapy with a combination tablet containing pioglitazone and metformin is considered appropriate the recommended starting dose is:

  • 15 mg/500 mg twice daily or 15 mg/850 mg once daily and gradually titrated, as needed, after assessing adequacy of therapeutic response and tolerability,
  • for patients with New York Heart Association (NYHA) Class I or Class II congestive heart failure: 15 mg/500 mg or 15 mg/850 mg once daily and gradually titrated, as needed, after assessing adequacy of therapeutic response and tolerability,
  • for patients inadequately controlled on metformin monotherapy: 15 mg/500 mg twice daily or 15 mg/850 mg once or twice daily (depending on the dose of metformin already being taken) and gradually titrated, as needed, after assessing adequacy of therapeutic response and tolerability,
  • for patients inadequately controlled on pioglitazone monotherapy: 15 mg/500 mg twice daily or 15 mg/850 mg once daily and gradually titrated, as needed, after assessing adequacy of therapeutic response and tolerability,
  • for patients who are changing from combination therapy of pioglitazone plus metformin as separate tablets: ACTOPLUS MET should be taken at doses that are as close as possible to the dose of pioglitazone and metformin already being taken.

ACTOPLUS MET may be titrated up to a maximum daily dose of 45 mg of pioglitazone and 2550 mg of metformin.

Metformin doses above 2000 mg may be better tolerated given three times a day.

After initiation of ACTOPLUS MET or with dose increase, monitor patients carefully for adverse reactions related to fluid retention such as weight gain, edema, and signs and symptoms of congestive heart failure. Liver tests (serum alanine and aspartate aminotransferases, alkaline phosphatase, and total bilirubin) should be obtained prior to initiating ACTOPLUS MET. Routine periodic monitoring of liver tests during treatment with ACTOPLUS MET is not recommended in patients without liver disease. Patients who have liver test abnormalities prior to initiation of ACTOPLUS MET or who are found to have abnormal liver tests while taking ACTOPLUS MET should be managed as described under Warnings and Precautions.

Concomitant Use With An Insulin Secretagogue Or Insulin

If hypoglycemia occurs in a patient coadministered ACTOPLUS MET and an insulin secretagogue (e.g., sulfonylurea), the dose of the insulin secretagogue should be reduced.

If hypoglycemia occurs in a patient coadministered ACTOPLUS MET and insulin, the dose of insulin should be decreased by 10% to 25%. Further adjustments to the insulin dose should be individualized based on glycemic response.

Concomitant Use With Strong CYP2C8 Inhibitors

Coadministration of pioglitazone (one of the ingredients in ACTOPLUS MET) and gemfibrozil, a strong CYP2C8 inhibitor, increases pioglitazone exposure approximately 3-fold. Therefore, the maximum recommended dose of ACTOPLUS MET is 15 mg/850 mg daily when used in combination with gemfibrozil or other strong CYP2C8 inhibitors.

Contraindications

  • Initiation in patients with established NYHA Class III or IV heart failure.
  • Renal impairment (e.g., serum creatinine levels ≥ 1.5 mg/dL [males], ≥ 1.4 mg/dL  [females], or abnormal creatinine clearance) which may also result from conditions  such as cardiovascular collapse (shock), acute myocardial infarction, and septicemia  .
  • Use in patients with known hypersensitivity to pioglitazone, metformin, or any other  component of ACTOPLUS MET.
  • Metabolic acidosis, including diabetic ketoacidosis. Diabetic ketoacidosis should be  treated with insulin.

Special warnings and precautions for use

WARNINGS

Included as part of the PRECAUTIONS section.

PRECAUTIONS

Congestive Heart Failure

Pioglitazone

Pioglitazone, like other thiazolidinediones, can cause dose-related fluid retention when used alone or in combination with other antidiabetic medications and is most common when pioglitazone is used in combination with insulin. Fluid retention may lead to or exacerbate congestive heart failure. Patients treated with ACTOPLUS MET should be observed for signs and symptoms of congestive heart failure. If congestive heart failure develops, it should be managed according to current standards of care and discontinuation or dose reduction of ACTOPLUS MET must be considered.

Lactic Acidosis

Metformin Hydrochloride

Lactic Acidosis

Lactic acidosis is a serious, metabolic complication that can occur due to metformin accumulation during treatment with ACTOPLUS MET and it is fatal in approximately 50% of cases. Lactic acidosis may also occur in association with a number of pathophysiologic conditions, including diabetes mellitus, and whenever there is significant tissue hypoperfusion and hypoxemia. Lactic acidosis is characterized by elevated blood lactate concentrations ( > 5 mmol/L), decreased blood pH, electrolyte disturbances with an increased anion gap, and an increased lactate/pyruvate ratio. When metformin is implicated as the cause of lactic acidosis, metformin plasma levels > 5 mcg/mL are generally found.

The reported incidence of lactic acidosis in patients receiving metformin hydrochloride is approximately 0.03 cases/1000 patient-years, with approximately 0.015 fatal cases/1000 patient-years. In more than 20,000 patient-years, exposure to metformin in clinical trials, there were no reports of lactic acidosis. Reported cases have occurred primarily in diabetic patients with significant renal impairment, including both intrinsic renal disease and renal hypoperfusion, often in the setting of multiple concomitant medical/surgical problems and multiple concomitant medications. Patients with congestive heart failure requiring pharmacologic management, particularly when accompanied by hypoperfusion and hypoxemia, are at increased risk of lactic acidosis. The risk of lactic acidosis increases with the degree of renal dysfunction and the patient's age. The risk of lactic acidosis may, therefore, be significantly decreased by regular monitoring of renal function in patients taking metformin. In particular, treatment of the elderly should be accompanied by careful monitoring of renal function. ACTOPLUS MET treatment should not be initiated in any patient unless measurement of creatinine clearance demonstrates that renal function is not reduced. In addition, metformin should be promptly withheld in the presence of any condition associated with hypoxemia, dehydration, or sepsis. Because impaired hepatic function may significantly limit the ability to clear lactate, metformin should generally be avoided in patients with clinical or laboratory evidence of hepatic impairment. Patients should be cautioned against excessive alcohol intake when taking metformin, because alcohol potentiates the effects of metformin on lactate metabolism. In addition, metformin should be temporarily discontinued prior to any intravascular radiocontrast study and for any surgical procedure necessitating restricted intake of food or fluids. Use of topiramate, a carbonic anhydrase inhibitor, in epilepsy and migraine prophylaxis may frequently cause dose-dependent metabolic acidosis and may exacerbate the risk of metformin-induced lactic acidosis.

The onset of lactic acidosis often is subtle, and accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, increasing somnolence, and nonspecific abdominal distress. There may be associated hypothermia, hypotension, and resistant bradyarrhythmias with more marked acidosis. Patients should be educated to promptly report these symptoms should they occur. If present, ACTOPLUS MET should be withdrawn until lactic acidosis is ruled out. Serum electrolytes, ketones, blood glucose, blood pH, lactate levels, and blood metformin levels may be useful. Once a patient is stabilized on any dose level of metformin, gastrointestinal symptoms, which are common during initiation of therapy, are unlikely to recur. Later occurrence of gastrointestinal symptoms could be due to lactic acidosis or other serious disease.

Levels of fasting venous plasma lactate above the upper limit of normal but less than 5 mmol/L in patients taking metformin do not necessarily indicate impending lactic acidosis and may be explainable by other mechanisms, such as poorly controlled diabetes or obesity, vigorous physical activity, or technical problems in sample handling.

Lactic acidosis should be suspected in any diabetic patient with metabolic acidosis lacking evidence of ketoacidosis (ketonuria and ketonemia).

Lactic acidosis is a medical emergency that must be treated in a hospital setting. In a patient with lactic acidosis who is taking metformin, the drug should be discontinued immediately and general supportive measures promptly instituted. Because metformin hydrochloride is dialyzable (with a clearance of up to 170 mL/min under good hemodynamic conditions), prompt hemodialysis is recommended to correct the acidosis and remove the accumulated metformin. Such management often results in prompt reversal of symptoms and recovery.

Edema

In controlled clinical trials with pioglitazone, edema was reported more frequently in patients treated with pioglitazone than in placebo-treated patients and is dose related. In postmarketing experience, reports of new onset or worsening of edema have been received.

ACTOPLUS MET should be used with caution in patients with edema. Because thiazolidinediones, including pioglitazone, can cause fluid retention, which can exacerbate or lead to congestive heart failure, ACTOPLUS MET should be used with caution in patients at risk for congestive heart failure. Patients treated with ACTOPLUS MET should be monitored for signs and symptoms of congestive heart failure.

Hypoglycemia

Patients receiving ACTOPLUS MET in combination with insulin or other antidiabetic medications (particularly insulin secretagogues such as sulfonylureas) may be at risk for hypoglycemia. A reduction in the dose of the concomitant antidiabetic medication may be necessary to reduce the risk of hypoglycemia. Hypoglycemia can also occur when caloric intake is deficient or when strenuous exercise is not compensated by caloric supplement. Elderly, debilitated, or malnourished patients, and those with adrenal or pituitary insufficiency or alcohol intoxication are particularly susceptible to hypoglycemic effects. Hypoglycemia may be difficult to recognize in the elderly, and in people who are taking beta-adrenergic blocking drugs.

Hepatic Effects

There have been postmarketing reports of fatal and nonfatal hepatic failure in patients taking pioglitazone, although the reports contain insufficient information necessary to establish the probable cause. There has been no evidence of drug-induced hepatotoxicity in the pioglitazone controlled clinical trial database to date.

Patients with type 2 diabetes may have fatty liver disease or cardiac disease with episodic congestive heart failure, both of which may cause liver test abnormalities, and they may also have other forms of liver disease, many of which can be treated or managed. Therefore, obtaining a liver test panel (serum alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase, and total bilirubin) and assessing the patient is recommended before initiating ACTOPLUS MET therapy.

In patients with abnormal liver tests, ACTOPLUS MET should be initiated with caution.

Measure liver tests promptly in patients who report symptoms that may indicate liver injury, including fatigue, anorexia, right upper abdominal discomfort, dark urine or jaundice. In this clinical context, if the patient is found to have abnormal liver tests (ALT greater than three times the upper limit of the reference range), ACTOPLUS MET treatment should be interrupted and investigation done to establish the probable cause. ACTOPLUS MET should not be restarted in these patients without another explanation for the liver test abnormalities.

Patients who have serum ALT greater than three times the reference range with serum total bilirubin greater than two times the reference range without alternative etiologies are at risk for severe drug-induced liver injury, and should not be restarted on ACTOPLUS MET. For patients with lesser elevations of serum ALT or bilirubin and with an alternate probable cause, treatment with ACTOPLUS MET can be used with caution.

Because impaired hepatic function has been associated with some cases of lactic acidosis ACTOPLUS MET should generally be avoided in patients with clinical or laboratory evidence of hepatic disease.

Urinary Bladder Tumors

Tumors were observed in the urinary bladder of male rats in the two-year carcinogenicity study. In two 3-year trials in which pioglitazone was compared to placebo or glyburide, there were 16/3656 (0.44%) reports of bladder cancer in patients taking pioglitazone compared to 5/3679 (0.14%) in patients not taking pioglitazone. After excluding patients in whom exposure to study drug was less than one year at the time of diagnosis of bladder cancer, there were six (0.16%) cases on pioglitazone and two (0.05%) cases on placebo.

A five-year interim report of an ongoing 10-year observational cohort study found a nonsignificant increase in the risk for bladder cancer in subjects ever exposed to pioglitazone, compared to subjects never exposed to pioglitazone (HR 1.2 [95% CI 0.9 - 1.5]). Compared to never exposure, a duration of pioglitazone therapy longer than 12 months was associated with an increase in risk (HR 1.4 [95% CI 0.9 - 2.1]), which reached statistical significance after more than 24 months of pioglitazone use (HR 1.4 [95% CI 1.03 - 2.0]). Interim results from this study suggested that taking pioglitazone longer than 12 months increased the relative risk of developing bladder cancer in any given year by 40%, which equates to an absolute increase of three cases in 10,000 (from approximately seven in 10,000 [without pioglitazone] to approximately 10 in 10,000 [with pioglitazone]).

There are insufficient data to determine whether pioglitazone is a tumor promoter for urinary bladder tumors. Consequently, ACTOPLUS MET should not be used in patients with active bladder cancer and the benefits of glycemic control versus unknown risks for cancer recurrence with ACTOPLUS MET should be considered in patients with a prior history of bladder cancer.

Fractures

In PROactive (the Prospective Pioglitazone Clinical Trial in Macrovascular Events), 5238 patients with type 2 diabetes and a history of macrovascular disease were randomized to pioglitazone (N=2605), force-titrated up to 45 mg daily or placebo (N=2633) in addition to standard of care. During a mean follow-up of 34.5 months, the incidence of bone fracture in females was 5.1% (44/870) for pioglitazone versus 2.5% (23/905) for placebo. This difference was noted after the first year of treatment and persisted during the course of the study. The majority of fractures observed in female patients were nonvertebral fractures including lower limb and distal upper limb. No increase in the incidence of fracture was observed in men treated with pioglitazone (1.7%) versus placebo (2.1%). The risk of fracture should be considered in the care of patients, especially female patients, treated with ACTOPLUS MET and attention should be given to assessing and maintaining bone health according to current standards of care.

Macular Edema

Macular edema has been reported in postmarketing experience in diabetic patients who were taking pioglitazone or another thiazolidinedione. Some patients presented with blurred vision or decreased visual acuity, but others were diagnosed on routine ophthalmologic examination.

Most patients had peripheral edema at the time macular edema was diagnosed. Some patients had improvement in their macular edema after discontinuation of the thiazolidinedione.

Patients with diabetes should have regular eye exams by an ophthalmologist according to current standards of care. Patients with diabetes who report any visual symptoms should be promptly referred to an ophthalmologist, regardless of the patient's underlying medications or other physical findings.

Ovulation

Therapy with pioglitazone, like other thiazolidinediones, may result in ovulation in some premenopausal anovulatory women. As a result, these patients may be at an increased risk for pregnancy while taking ACTOPLUS MET. This effect has not been investigated in clinical trials, so the frequency of this occurrence is not known. Adequate contraception in all premenopausal women treated with ACTOPLUS MET is recommended.

Monitoring Of Renal Function

Metformin is substantially excreted by the kidney, and the risk of metformin accumulation and lactic acidosis increases with the degree of impairment of renal function. Therefore, ACTOPLUS MET is contraindicated in patients with renal impairment.

Before initiation of therapy with ACTOPLUS MET and at least annually thereafter, renal function should be assessed and verified as normal. In patients in whom development of renal dysfunction is anticipated (e.g., elderly), renal function should be assessed more frequently and ACTOPLUS MET discontinued if evidence of renal impairment is present.

Use Of Concomitant Medications That May Affect Renal Function Or Metformin Disposition

Concomitant medication(s) that may affect renal function or result in significant hemodynamic change or may interfere with the disposition of metformin, such as cationic drugs that are eliminated by renal tubular secretion, should be used with caution.

Radiological Studies And Surgical Procedures

Radiologic studies involving the use of intravascular iodinated contrast materials (for example, intravenous urogram, intravenous cholangiography, angiography, and computed tomography (CT) scans with intravascular contrast materials) can lead to acute alteration of renal function and have been associated with lactic acidosis in patients receiving metformin. Therefore, in patients in whom any such study is planned, ACTOPLUS MET should be discontinued at the time of or prior to the procedure, and withheld for 48 hours subsequent to the procedure and reinstituted only after renal function has been re-evaluated and found to be normal.

Hypoxic States

Cardiovascular collapse (shock) from whatever cause, acute congestive heart failure, acute myocardial infarction and other conditions characterized by hypoxemia have been associated with lactic acidosis and may also cause prerenal azotemia. When such events occur in patients receiving ACTOPLUS MET therapy, the drug should be promptly discontinued.

Surgical Procedures

Use of ACTOPLUS MET should be temporarily suspended for any surgical procedure (except minor procedures not associated with restricted intake of food and fluids) and should not be restarted until the patient's oral intake has resumed and renal function has been evaluated as normal.

Alcohol Intake

Alcohol is known to potentiate the effect of metformin on lactate metabolism. Patients, therefore, should be warned against excessive alcohol intake, acute or chronic, while receiving ACTOPLUS MET.

Vitamin B12 Levels

In controlled clinical trials of metformin of 29 weeks' duration, a decrease to subnormal levels of previously normal serum vitamin B12 levels, without clinical manifestations, was observed in approximately 7% of patients. Such decrease, possibly due to interference with B12 absorption from the B12-intrinsic factor complex, is, however, very rarely associated with anemia and appears to be rapidly reversible with discontinuation of metformin or vitamin B12 supplementation. Measurement of hematologic parameters on an annual basis is advised in patients on ACTOPLUS MET and any apparent abnormalities should be appropriately investigated and managed. Certain individuals (those with inadequate vitamin B12 or calcium intake or absorption) appear to be predisposed to developing subnormal vitamin B12 levels. In these patients, routine serum vitamin B12 measurements at two-to three-year intervals may be useful.

Macrovascular Outcomes

There have been no clinical studies establishing conclusive evidence of macrovascular risk reduction with ACTOPLUS MET or any other oral antidiabetic drug.

Patient Counseling Information

See FDA-Approved Patient Labeling (Medication Guide)

  • It is important to instruct patients to adhere to dietary instructions and to have blood glucose and glycosylated hemoglobin tested regularly. During periods of stress such as fever, trauma, infection, or surgery, medication requirements may change and patients should be reminded to seek medical advice promptly.
  • Tell patients to promptly report any sign of macroscopic hematuria or other symptoms such as dysuria or urinary urgency that develop or increase during treatment as these may be due to bladder cancer.
  • Explain to patients the risks of lactic acidosis, its symptoms and conditions that predispose to its development, as noted in the WARNINGS AND PRECAUTIONS section. Advise patients to discontinue ACTOPLUS MET immediately and to promptly notify their healthcare professional if unexplained hyperventilation, myalgia, gastrointestinal symptoms, malaise, unusual somnolence, or other nonspecific symptoms occur.
  • Counsel patients against excessive alcohol intake while receiving ACTOPLUS MET.
  • Inform patients to immediately report symptoms of an unusually rapid increase in weight or edema, shortness of breath, or other symptoms of heart failure while receiving ACTOPLUS MET.
  • Tell patients to promptly stop taking ACTOPLUS MET and seek immediate medical advice if there is unexplained nausea, vomiting, abdominal pain, fatigue, anorexia, or dark urine as these symptoms may be due to hepatotoxicity.
  • Inform patients about the importance of regular testing of renal function and hematologic parameters when receiving treatment with ACTOPLUS MET.
  • Inform patients that therapy with a thiazolidinedione, which is the active pioglitazone component of the ACTOPLUS MET tablet, may result in ovulation in some premenopausal anovulatory women. As a result, these patients may be at an increased risk for pregnancy while taking ACTOPLUS MET. Recommend adequate contraception for all premenopausal women who are prescribed ACTOPLUS MET.
  • Patients should be advised to notify their health practitioner or call the Poison Control Center immediately in case of ACTOPLUS MET overdose.
  • Combination antihyperglycemic therapy may cause hypoglycemia. When initiating ACTOPLUS MET, the risks of hypoglycemia, its symptoms and treatment, and conditions that predispose to its development should be explained to patients and their family members.
  • Patients should be told to take ACTOPLUS MET as prescribed and instructed that any change in dosing should only be done if directed by their physician. If a dose is missed on one day, the dose should not be doubled the following day.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment Of Fertility

ACTOPLUS MET

No animal studies have been conducted with ACTOPLUS MET. The following data are based on findings in studies performed with pioglitazone or metformin individually.

Pioglitazone

A two-year carcinogenicity study was conducted in male and female rats at oral doses up to 63 mg/kg (approximately 14 times the maximum recommended human oral dose of 45 mg based on mg/m²). Drug-induced tumors were not observed in any organ except for the urinary bladder of male rats. Benign and/or malignant transitional cell neoplasms were observed in male rats at 4 mg/kg/day and above (approximately equal to the maximum recommended human oral dose based on mg/m²). Urinary calculi with subsequent irritation and hyperplasia were postulated as the mechanism for bladder tumors observed in male rats. A two-year mechanistic study in male rats utilizing dietary acidification to reduce calculi formation was completed in 2009. Dietary acidification decreased but did not abolish the hyperplastic changes in the bladder. The presence of calculi exacerbated the hyperplastic response to pioglitazone but was not considered the primary cause of the hyperplastic changes.

The relevance to humans of the bladder findings in the male rat cannot be excluded.

A two-year carcinogenicity study was also conducted in male and female mice at oral doses up to 100 mg/kg/day (approximately 11 times the maximum recommended human oral dose based on mg/m²). No drug-induced tumors were observed in any organ.

Pioglitazone hydrochloride was not mutagenic in a battery of genetic toxicology studies, including the Ames bacterial assay, a mammalian cell forward gene mutation assay (CHO/HPRT and AS52/XPRT), an in vitro cytogenetics assay using CHL cells, an unscheduled DNA synthesis assay, and an in vivo micronucleus assay.

No adverse effects upon fertility were observed in male and female rats at oral doses up to 40 mg/kg pioglitazone hydrochloride daily prior to and throughout mating and gestation (approximately nine times the maximum recommended human oral dose based on mg/m²).

Metformin Hydrochloride

Long-term carcinogenicity studies have been performed in rats (dosing duration of 104 weeks) and mice (dosing duration of 91 weeks) at doses up to and including 900 mg/kg/day and 1500 mg/kg/day, respectively. These doses are both approximately four times a human daily dose of 2000 mg of the metformin component of ACTOPLUS MET based on body surface area comparisons. No evidence of carcinogenicity with metformin was found in either male or female mice. Similarly, there was no tumorigenic potential observed with metformin in male rats. There was, however, an increased incidence of benign stromal uterine polyps in female rats treated with 900 mg/kg/day.

There was no evidence of mutagenic potential of metformin in the following in vitro tests: Ames test (S. typhimurium), gene mutation test (mouse lymphoma cells), or chromosomal aberrations test (human lymphocytes). Results in the in vivo mouse micronucleus test were also negative.

Fertility of male or female rats was unaffected by metformin when administered at doses as high as 600 mg/kg/day, which is approximately three times the maximum recommended human daily dose of the metformin component of ACTOPLUS MET based on body surface area comparisons.

Use In Specific Populations

Pregnancy

Pregnancy Category C

There are no adequate and well-controlled studies of ACTOPLUS MET or its individual components in pregnant women. Animal studies using pioglitazone show increased rates of post-implantation loss, delayed development, reduced fetal weights, and delayed parturition at doses 10 to 40 times the maximum recommended human dose. ACTOPLUS MET should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Pioglitazone

Clinical Considerations

Abnormal blood glucose concentrations during pregnancy are associated with a higher incidence of congenital anomalies, as well as increased neonatal morbidity and mortality. Most experts recommend the use of insulin during pregnancy to maintain blood glucose concentrations as close to normal as possible for patients with diabetes.

Animal Data

In animal reproductive studies, pregnant rats and rabbits received pioglitazone at doses up to approximately 17 (rat) and 40 (rabbit) times the maximum recommended human oral dose (MRHD) based on body surface area (mg/m²); no teratogenicity was observed. Increases in embryotoxicity (increased postimplantation losses, delayed development, reduced fetal weights, and delayed parturition) occurred in rats that received oral doses approximately 10 or more times the MRHD (mg/m² basis). No functional or behavioral toxicity was observed in rat offspring. When pregnant rats received pioglitazone during late gestation and lactation, delayed postnatal development, attributed to decreased body weight, occurred in rat offspring at oral maternal doses approximately 2 or more times the MRHD (mg/m² basis). In rabbits, embryotoxicity occurred at oral doses approximately 40 times the MRHD (mg/m² basis).

Metformin Hydrochloride

Metformin was not teratogenic in rats and rabbits at doses up to 600 mg/kg/day. This represents an exposure of about two and six times a human daily dose of 2000 mg based on body surface area comparisons for rats and rabbits, respectively. However, because animal reproduction studies are not always predictive of human response, metformin should not be used during pregnancy unless clearly needed.

Labor And Delivery

The effect of ACTOPLUS MET on labor and delivery in humans is not known.

Nursing Mothers

No studies have been conducted with the combined components of ACTOPLUS MET. In studies performed with the individual components, both pioglitazone and metformin are secreted in the milk of lactating rats. It is not known whether pioglitazone and/or metformin are secreted in human milk. Because many drugs are excreted in human milk, and because of the potential for ACTOPLUS MET to cause serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue ACTOPLUS MET, taking into account the importance of ACTOPLUS MET to the mother.

Pediatric Use

Safety and effectiveness of ACTOPLUS MET in pediatric patients have not been established.

ACTOPLUS MET is not recommended for use in pediatric patients based on adverse effects observed in adults, including fluid retention and congestive heart failure, fractures, and urinary bladder tumors.

Geriatric Use

Pioglitazone

A total of 92 patients (15.2%) treated with pioglitazone in the three pooled 16-to 26-week double-blind, placebo-controlled, monotherapy trials were ≥ 65 years old and two patients (0.3%) were ≥ 75 years old. In the two pooled 16-to 24-week add-on to sulfonylurea trials, 201 patients (18.7%) treated with pioglitazone were ≥ 65 years old and 19 (1.8%) were ≥ 75 years old. In the two pooled 16-to 24-week add-on to metformin trials, 155 patients (15.5%) treated with pioglitazone were ≥ 65 years old and 19 (1.9%) were ≥ 75 years old. In the two pooled 16-to 24-week add-on to insulin trials, 272 patients (25.4%) treated with pioglitazone were ≥ 65 years old and 22 (2.1%) were ≥ 75 years old.

In PROactive Trial, 1068 patients (41.0%) treated with pioglitazone were ≥ 65 years old and 42 (1.6%) were ≥ 75 years old.

In pharmacokinetic studies with pioglitazone, no significant differences were observed in pharmacokinetic parameters between elderly and younger patients.

Although clinical experiences have not identified differences in effectiveness and safety between the elderly ( ≥ 65 years) and younger patients, these conclusions are limited by small sample sizes for patients ≥ 75 years old.

Metformin Hydrochloride

Controlled clinical studies of metformin did not include sufficient numbers of elderly patients to determine whether they respond differently from younger patients, although other reported clinical experience has not identified differences in responses between the elderly and young patients. Metformin is known to be substantially excreted by the kidney and because the risk of serious adverse reactions to the drug is greater in patients with impaired renal function, ACTOPLUS MET should only be used in patients with normal renal function. Because aging is associated with reduced renal function, ACTOPLUS MET should be used with caution as age increases. Care should be taken in dose selection and should be based on careful and regular monitoring of renal function. Generally, elderly patients should not be titrated to the maximum dose of ACTOPLUS MET.

Interaction with other medicinal products and other forms of interaction

SIDE EFFECTS

The following serious adverse reactions are discussed elsewhere in the labeling:

  • Congestive heart failure
  • Lactic acidosis
  • Edema
  • Fractures

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Pioglitazone

Over 8500 patients with type 2 diabetes have been treated with pioglitazone in randomized, double-blind, controlled clinical trials, including 2605 patients with type 2 diabetes and macrovascular disease treated with pioglitazone from the PROactive clinical trial. In these trials, over 6000 patients have been treated with pioglitazone for six months or longer, over 4500 patients have been treated with pioglitazone for one year or longer, and over 3000 patients have been treated with pioglitazone for at least two years.

In six pooled 16-to 26-week placebo-controlled monotherapy and 16-to 24-week add-on combination therapy trials, the incidence of withdrawals due to adverse events was 4.5% for patients treated with pioglitazone and 5.8% for comparator-treated patients.

The most common adverse events leading to withdrawal were related to inadequate glycemic control, although the incidence of these events was lower (1.5%) with pioglitazone than with placebo (3.0%).

In the PROactive trial, the incidence of withdrawals due to adverse events was 9.0% for patients treated with pioglitazone and 7.7% for placebo-treated patients. Congestive heart failure was the most common serious adverse event leading to withdrawal occurring in 1.3% of patients treated with pioglitazone and 0.6% of patients treated with placebo.

Common Adverse Events: 16-to 26-Week Monotherapy Trials

A summary of the incidence and type of common adverse events reported in three pooled 16-to 26-week placebo-controlled monotherapy trials of pioglitazone is provided in Table 1. Terms that are reported represent those that occurred at an incidence of > 5% and more commonly in patients treated with pioglitazone than in patients who received placebo. None of these adverse events were related to the pioglitazone dose.

Table 1: Three Pooled 16-to 26-Week Placebo-Controlled Clinical Trials of Pioglitazone Monotherapy: Adverse Events Reported at an Incidence > 5% and More Commonly in Patients Treated with Pioglitazone than in Patients Treated with Placebo

  % of Patients
Placebo
N=259
Pioglitazone
N=606
Upper Respiratory Tract Infection 8.5 13.2
Headache 6.9 9.1
Sinusitis 4.6 6.3
Myalgia 2.7 5.4
Pharyngitis 0.8 5.1

Common Adverse Events: 16-to 24-Week Add-on Combination Therapy Trials

A summary of the overall incidence and types of common adverse events reported in trials of pioglitazone add-on to metformin is provided in Table 2. Terms that are reported represent those that occurred at an incidence of > 5% and more commonly with the highest tested dose of pioglitazone.

Table 2: 16-to 24-Week Clinical Trials of Pioglitazone Add-on to Metformin

  16-Week Placebo-Controlled Trial Adverse Events Reported in > 5% of Patients and More Commonly in Patients Treated with Pioglitazone + Metformin than in Patients Treated with Placebo + Metformin
% of Patients
Placebo + Metformin
N=160
Pioglitazone 30 mg + Metformin
N=168
Edema 2.5 6.0
Headache 1.9 6.0
  24-Week Non-Controlled Double-Blind Trial Adverse Events Reported in > 5% of Patients and More Commonly in Patients Treated with Pioglitazone 45 mg + Metformin than in Patients Treated with Pioglitazone 30 mg + Metformin
% of Patients
Pioglitazone 30 mg + Metformin
N=411
Pioglitazone 45 mg + Metformin
N=416
Upper Respiratory Tract Infection 12.4 13.5
Edema 5.8 13.9
Headache 5.4 5.8
Weight Increased 2.9 6.7
Note: The preferred terms of edema peripheral, generalized edema, pitting edema, and fluid retention were combined to form the aggregate term of “edema.”

Common Adverse Events: 24-Week ACTOPLUS MET Clinical Trial

Table 3 summarizes the incidence and types of adverse reactions reported in a controlled, 24-week double-blind clinical trial of ACTOPLUS MET dosed twice daily in patients with inadequate glycemic control on diet and exercise (N=600).

Table 3: Adverse Events ( ≥ 5% for ACTOPLUS MET) Reported by Patients with Inadequate Glycemic Control on Diet and Exercise in a 24-Week Double-Blind Clinical Trial of ACTOPLUS MET Administered Twice Daily

% of Patients
  ACTOPLUS MET 15/850 mg Twice Daily
N=201
Pioglitazone 15 mg Twice Daily
N=190
Metformin 850 mg Twice Daily
N=209
Diarrhea 9.0 2.6 15.3
Headache 5.5 2.6 4.8

In this 24-week trial, abdominal pain was reported in 2.0% of patients in the ACTOPLUS MET group, 1.6% in the pioglitazone monotherapy group and 3.3% in the metformin monotherapy group.

Common Adverse Events: PROactive Trial

A summary of the overall incidence and types of common adverse events reported in the PROactive trial is provided in Table 4. Terms that are reported represent those that occurred at an incidence of > 5% and more commonly in patients treated with pioglitazone than in patients who received placebo.

Table 4: PROactive Trial: Incidence and Types of Adverse Events Reported in > 5% of Patients Treated with Pioglitazone and More Commonly than Placebo

  % of Patients
Placebo
N=2633
Pioglitazone
N=2605
Hypoglycemia 18.8 27.3
Edema 15.3 26.7
Cardiac Failure 6.1 8.1
Pain in Extremity 5.7 6.4
Back Pain 5.1 5.5
Chest Pain 5.0 5.1

Mean duration of patient follow-up was 34.5 months.

Congestive Heart Failure

A summary of the incidence of adverse events related to congestive heart failure is provided in Table 5 for the 16-to 24-week add-on to metformin trials. None of the events were fatal.

Table 5: Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) Patients Treated with Pioglitazone or Placebo Added on to Metformin

  Number (%) of Patients
Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks)
Placebo + Metformin
N=160
Pioglitazone 30 mg + Metformin
N=168
Pioglitazone 30 mg + Metformin
N=411
Pioglitazone 45 mg + Metformin
N=416
At least one congestive heart failure event 0 1 (0.6%) 0 1 (0.2%)
Hospitalized 0 1 (0.6%) 0 1 (0.2%)

Table 6: Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF)

Patients Treated with Pioglitazone or Placebo Added on to a Sulfonylurea
  Number (%) of Patients
Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks)
Placebo + Sulfonylurea
N=187
Pioglitazone 15 mg + Sulfonylurea
N=184
Pioglitazone 30 mg + Sulfonylurea
N=189
Pioglitazone 30 mg + Sulfonylurea
N=351
Pioglitazone 45 mg + Sulfonylurea
N=351
At least one congestive heart failure event 2 (1.1%) 0 0 1 (0.3%) 6 (1.7%)
Hospitalized 2 (1.1%) 0 0 0 2 (0.6%)
Patients Treated with Pioglitazone or Placebo Added on to Insulin
  Number (%) of Patients
Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks)
Placebo + Insulin N=187 Pioglitazone 15 mg + Insulin N=191 Pioglitazone 30 mg + Insulin N=188 Pioglitazone 30 mg + Insulin N=345 Pioglitazone 45 mg + Insulin N=345
At least one congestive heart failure event 0 2 (1.0%) 2 (1.1%) 3 (0.9%) 5 (1.4%)
Hospitalized 0 2 (1.0%) 1 (0.5%) 1 (0.3%) 3 (0.9%)
Patients Treated with Pioglitazone or Placebo Added on to Metformin
  Number (%) of Patients
Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks)
Placebo + Metformin N=160 Pioglitazone 30 mg + Metformin N=168 Pioglitazone 30 mg + Metformin N=411 Pioglitazone 45 mg + Metformin N=416
At least one congestive heart failure event 0 1 (0.6%) 0 1 (0.2%)
Hospitalized 0 1 (0.6%) 0 1 (0.2%)

Table 7: Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) in Patients with NYHA Class II or III Congestive Heart Failure Treated with Pioglitazone or Glyburide

  Number (%) of Subjects
Pioglitazone
N=262
Glyburide
N=256
Death due to cardiovascular causes (adjudicated) 5 (1.9%) 6 (2.3%)
Overnight hospitalization for worsening CHF (adjudicated) 26 (9.9%) 12 (4.7%)
Emergency room visit for CHF (adjudicated) 4 (1.5%) 3 (1.2%)
Patients experiencing CHF progression during study 35 (13.4%) 21 (8.2%)

Congestive heart failure events leading to hospitalization that occurred during the PROactive trial are summarized in Table 8.

Table 8: Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) in PROactive Trial

  Number (%) of Patients
Placebo
N=2633
Pioglitazone
N=2605
At least one hospitalized congestive heart failure event 108 (4.1%) 149 (5.7%)
Fatal 22 (0.8%) 25 (1.0%)
Hospitalized, nonfatal 86 (3.3%) 124 (4.7%)

Cardiovascular Safety

In the PROactive trial, 5238 patients with type 2 diabetes and a history of macrovascular disease were randomized to pioglitazone (N=2605), force-titrated up to 45 mg daily or placebo (N=2633) in addition to standard of care. Almost all patients (95%) were receiving cardiovascular medications (beta blockers, ACE inhibitors, angiotensin II receptor blockers, calcium channel blockers, nitrates, diuretics, aspirin, statins, and fibrates). At baseline, patients had a mean age of 62 years, mean duration of diabetes of 9.5 years, and mean HbA1c of 8.1%. Mean duration of follow-up was 34.5 months.

The primary objective of this trial was to examine the effect of pioglitazone on mortality and macrovascular morbidity in patients with type 2 diabetes mellitus who were at high risk for macrovascular events. The primary efficacy variable was the time to the first occurrence of any event in a cardiovascular composite endpoint that included all-cause mortality, nonfatal myocardial infarction (MI) including silent MI, stroke, acute coronary syndrome, cardiac intervention including coronary artery bypass grafting or percutaneous intervention, major leg amputation above the ankle, and bypass surgery or revascularization in the leg. A total of 514 (19.7%) patients treated with pioglitazone and 572 (21.7%) placebo-treated patients experienced at least one event from the primary composite endpoint (HR 0.90; 95% CI: 0.80, 1.02; p=0.10).

Although there was no statistically significant difference between pioglitazone and placebo for the three-year incidence of a first event within this composite, there was no increase in mortality or in total macrovascular events with pioglitazone. The number of first occurrences and total individual events contributing to the primary composite endpoint is shown in Table 9.

Table 9: PROactive Trial: Number of First and Total Events for Each Component Within the Cardiovascular Composite Endpoint

Cardiovascular Events Placebo
N=2633
Pioglitazone
N=2605
First Events n (%) Total events n First Events n (%) Total events n
Any event 572 (21.7) 900 514 (19.7) 803
  All-cause mortality 122 (4.6) 186 110 (4.2) 177
  Nonfatal myocardial infarction (MI) 118 (4.5) 157 105 (4.0) 131
  Stroke 96 (3.6) 119 76 (2.9) 92
  Acute coronary syndrome 63 (2.4) 78 42 (1.6) 65
  Cardiac intervention (CABG/PCI) 101 (3.8) 240 101 (3.9) 195
  Major leg amputation 15 (0.6) 28 9 (0.3) 28
  Leg revascularization 57 (2.2) 92 71 (2.7) 115
CABG = coronary artery bypass grafting; PCI = percutaneous intervention

Weight Gain

Dose-related weight gain occurs when pioglitazone is used alone or in combination with other antidiabetic medications. The mechanism of weight gain is unclear but probably involves a combination of fluid retention and fat accumulation.

Tables 10, 11, and 12 summarize the changes in body weight with pioglitazone and placebo in the 16-to 26-week randomized, double-blind monotherapy and 16-to 24-week combination add-on therapy trials, the PROactive trial, and the 24-week ACTOPLUS MET trial.

Table 10: Weight Changes (kg) from Baseline During Randomized, Double-Blind Clinical Trials

    Control Group (Placebo) Pioglitazone 15 mg Pioglitazone 30 mg
Median (25th, 75th percentile) Median (25th, 75th percentile) Median (25th, 75th percentile)
Monotherapy (16 to 26 weeks)   -1.4 (-2.7, 0.0) N=256 0.9 (-0.5, 3.4) N=79 1.0 (-0.9, 3.4) N=188
Combination Therapy (16 to 24 weeks) Sulfonylurea -0.5 (-1.8, 0.7) N=187 2.0 (0.2, 3.2) N=183 3.1 (1.1, 5.4) N=528
Metformin -1.4 (-3.2, 0.3) N=160 N/A 0.9 (-1.3, 3.2) N=567
Insulin 0.2 (-1.4, 1.4) N=182 2.3 (0.5, 4.3) N=190 3.3 (0.9, 6.3) N=522

Table 11: Median Change in Body Weight in Patients Treated with Pioglitazone Versus Patients Treated with Placebo During the Double-Blind Treatment Period in the PROactive Trial

  Placebo Pioglitazone
Median (25th, 75th percentile) Median (25th, 75th percentile)
Change from baseline to final visit (kg) -0.5 (-3.3, 2.0) N=2581 +3.6 (0.0, 7.5) N=2560
Note: Median exposure for both pioglitazone and placebo was 2.7 years.

Table 12: Weight Changes (kg) from Baseline During Double-Blind Clinical Trial with ACTOPLUS MET in Patients with Inadequate Glycemic Control on Diet and Exercise

  ACTOPLUS MET 15/850 mg Twice Daily Pioglitazone 15 mg Twice Daily Metformin 850 mg Twice Daily
Median (25th , 75th percentile) Median (25th , 75th percentile) Median (25th , 75th percentile)
Change from baseline to final visit (kg) 1.00 (-1.0, 3.0) N=198 1.35 (-0.7, 4.1) N=178 -1.00 (-2.6, 0.4) N=203
Note: Trial duration of 24 weeks.

Edema

Edema induced from taking pioglitazone is reversible when pioglitazone is discontinued. The edema usually does not require hospitalization unless there is coexisting congestive heart failure.

In the 24-week ACTOPLUS MET trial, edema was reported in 3.0% of patients in the ACTOPLUS MET group, 4.2% in the pioglitazone monotherapy group, and 1.4% in the metformin monotherapy group.

A summary of the frequency and types of edema adverse events occurring in clinical investigations of pioglitazone is provided in Table 13.

Table 13: Adverse Events of Edema in Patients Treated with Pioglitazone

    Number (%) of Patients
Placebo Pioglitazone 15 mg Pioglitazone 30 mg
Monotherapy (16 to 26 weeks)   3 (1.2%) N=259 2 (2.5%) N= 81 13 (4.7%) N= 275
Combined Therapy (16 to 24 weeks) Sulfonylurea 4 (2.1%) N=187 3 (1.6%) N=184 61 (11.3%) N=540
Metformin 4 (2.5%) N=160 N/A 34 (5.9%) N=579
Insulin 13 (7.0%) N=187 24 (12.6%) N=191 109 (20.5%) N=533
Note: The preferred terms of edema peripheral, generalized edema, pitting edema, and fluid retention were combined to form the aggregate term of “edema.”

Table 14: Adverse Events of Edema in Patients in the PROactive Trial

Number (%) of Patients
Placebo
N=2633
Pioglitazone
N=2605
419 (15.9%) 712 (27.3%)
Note: The preferred terms of edema peripheral, generalized edema, pitting edema, and fluid retention were combined to form the aggregate term of “edema.”

Hepatic Effects

There has been no evidence of pioglitazone-induced hepatotoxicity in the pioglitazone controlled clinical trial database to date. One randomized, double-blind, three-year trial comparing pioglitazone to glyburide as add-on to metformin and insulin therapy was specifically designed to evaluate the incidence of serum ALT elevation to greater than three times the upper limit of the reference range, measured every eight weeks for the first 48 weeks of the trial then every 12 weeks thereafter. A total of 3/1051 (0.3%) patients treated with pioglitazone and 9/1046 (0.9%) patients treated with glyburide developed ALT values greater than three times the upper limit of the reference range. None of the patients treated with pioglitazone in the pioglitazone controlled clinical trial database to date have had a serum ALT greater than three times the upper limit of the reference range and a corresponding total bilirubin greater than two times the upper limit of the reference range, a combination predictive of the potential for severe drug-induced liver injury.

Hypoglycemia

In the pioglitazone clinical trials, adverse events of hypoglycemia were reported based on clinical judgment of the investigators and did not require confirmation with fingerstick glucose testing.

In the 16-week add-on to sulfonylurea trial, the incidence of reported hypoglycemia was 3.7% with pioglitazone 30 mg and 0.5% with placebo. In the 16-week add-on to insulin trial, the incidence of reported hypoglycemia was 7.9% with pioglitazone 15 mg, 15.4% with pioglitazone 30 mg, and 4.8% with placebo.

The incidence of reported hypoglycemia was higher with pioglitazone 45 mg compared to pioglitazone 30 mg in both the 24-week add-on to sulfonylurea trial (15.7% versus 13.4%) and in the 24-week add-on to insulin trial (47.8% versus 43.5%).

Three patients in these four trials were hospitalized due to hypoglycemia. All three patients were receiving pioglitazone 30 mg (0.9%) in the 24-week add-on to insulin trial. An additional 14 patients reported severe hypoglycemia (defined as causing considerable interference with patient's usual activities) that did not require hospitalization. These patients were receiving pioglitazone 45 mg in combination with sulfonylurea (n=2) or pioglitazone 30 mg or 45 mg in combination with insulin (n=12).

Urinary Bladder Tumors

Tumors were observed in the urinary bladder of male rats in the two-year carcinogenicity study. In two 3-year trials in which pioglitazone was compared to placebo or glyburide, there were 16/3656 (0.44%) reports of bladder cancer in patients taking pioglitazone compared to 5/3679 (0.14%) in patients not taking pioglitazone. After excluding patients in whom exposure to study drug was less than one year at the time of diagnosis of bladder cancer, there were six (0.16%) cases on pioglitazone and two (0.05%) cases on placebo. There are too few events of bladder cancer to establish causality.

Metformin Hydrochloride

In a double-blind clinical study of metformin in patients with type 2 diabetes, a total of 141 patients received metformin therapy (up to 2550 mg per day) and 145 patients received placebo. Adverse reactions reported in greater than 5% of the metformin patients, and that were more common in metformin than placebo-treated patients, are listed in Table 15. In this trial, diarrhea led to discontinuation of study medication in 6% of patients treated with metformin.

Table 15: Most Common Adverse Reactions ( > 5.0%) in a Placebo-Controlled Clinical Study of Metformin Monotherapy*

Adverse Reaction Metformin Monotherapy
(n=141)
Placebo
(n=145)
% of Patients
Diarrhea 53.2 11.7
Nausea/Vomiting 25.5 8.3
Flatulence 12.1 5.5
Asthenia 9.2 5.5
Indigestion 7.1 4.1
Abdominal Discomfort 6.4 4.8
Headache 5.7 4.8
*Reactions that were more common in metformin than placebo-treated patients.

Laboratory Abnormalities

Hematologic Effects

Pioglitazone may cause decreases in hemoglobin and hematocrit. In placebo-controlled monotherapy trials, mean hemoglobin values declined by 2% to 4% in patients treated with pioglitazone compared with a mean change in hemoglobin of -1% to +1% in placebo-treated patients. These changes primarily occurred within the first four to 12 weeks of therapy and remained relatively constant thereafter. These changes may be related to increased plasma volume associated with pioglitazone therapy and are not likely to be associated with any clinically significant hematologic effects.

Vitamin B12 Concentrations

Metformin may lower serum vitamin B12 concentrations. Measurement of hematologic parameters on an annual basis is advised in patients on ACTOPLUS MET and any apparent abnormalities should be appropriately investigated and managed.

Creatine Phosphokinase

During protocol-specified measurement of serum creatine phosphokinase (CPK) in pioglitazone clinical trials, an isolated elevation in CPK to greater than 10 times the upper limit of the reference range was noted in nine (0.2%) patients treated with pioglitazone (values of 2150 to 11400 IU/L) and in no comparator-treated patients. Six of these nine patients continued to receive pioglitazone, two patients were noted to have the CPK elevation on the last day of dosing, and one patient discontinued pioglitazone due to the elevation. These elevations resolved without any apparent clinical sequelae. The relationship of these events to pioglitazone therapy is unknown.

Postmarketing Experience

Pioglitazone

The following adverse reactions have been identified during post-approval use of pioglitazone. Because these reactions are reported voluntarily from a population of uncertain size, it is generally not possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

  • New onset or worsening diabetic macular edema with decreased visual acuity.
  • Fatal and nonfatal hepatic failure.

Postmarketing reports of congestive heart failure have been reported in patients treated with pioglitazone, both with and without previously known heart disease and both with and without concomitant insulin administration.

In postmarketing experience, there have been reports of unusually rapid increases in weight and increases in excess of that generally observed in clinical trials. Patients who experience such increases should be assessed for fluid accumulation and volume-related events such as excessive edema and congestive heart failure.

DRUG INTERACTIONS

Strong CYP2C8 Inhibitors

An inhibitor of CYP2C8 (e.g., gemfibrozil) significantly increases the exposure (area under the serum concentration-time curve or AUC) and half-life (t½) of pioglitazone. Therefore, the maximum recommended dose of pioglitazone is 15 mg daily if used in combination with gemfibrozil or other strong CYP2C8 inhibitors.

CYP2C8 Inducers

An inducer of CYP2C8 (e.g., rifampin) may significantly decrease the exposure (AUC) of pioglitazone. Therefore, if an inducer of CYP2C8 is started or stopped during treatment with pioglitazone, changes in diabetes treatment may be needed based on clinical response without exceeding the maximum recommended daily dose of 45 mg for pioglitazone.

Carbonic Anhydrase Inhibitors

Topiramate or other carbonic anhydrase inhibitors (e.g., zonisamide, acetazolamide or dichlorphenamide) frequently decrease serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of these drugs may induce metabolic acidosis. Use these drugs with caution in patients treated with metformin, as the risk of lactic acidosis may increase.

Cationic Drugs

Cationic drugs (e.g., amiloride, digoxin, morphine, procainamide, quinidine, quinine, ranitidine, triamterene, trimethoprim, or vancomycin) that are eliminated by renal tubular secretion theoretically have the potential for interaction with metformin by competing for common renal tubular transport systems. Although such interactions remain theoretical (except for cimetidine), careful patient monitoring and dose adjustment of ACTOPLUS MET and/or the interfering drug is recommended in patients who are taking cationic medications that are excreted via the proximal renal tubular secretory system.

Drugs Affecting Glycemic Control

Certain drugs tend to produce hyperglycemia and may lead to loss of glycemic control. These drugs include the thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives,

Fertility, pregnancy and lactation

Pregnancy Category C

There are no adequate and well-controlled studies of ACTOPLUS MET or its individual components in pregnant women. Animal studies using pioglitazone show increased rates of post-implantation loss, delayed development, reduced fetal weights, and delayed parturition at doses 10 to 40 times the maximum recommended human dose. ACTOPLUS MET should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Pioglitazone

Clinical Considerations

Abnormal blood glucose concentrations during pregnancy are associated with a higher incidence of congenital anomalies, as well as increased neonatal morbidity and mortality. Most experts recommend the use of insulin during pregnancy to maintain blood glucose concentrations as close to normal as possible for patients with diabetes.

Animal Data

In animal reproductive studies, pregnant rats and rabbits received pioglitazone at doses up to approximately 17 (rat) and 40 (rabbit) times the maximum recommended human oral dose (MRHD) based on body surface area (mg/m²); no teratogenicity was observed. Increases in embryotoxicity (increased postimplantation losses, delayed development, reduced fetal weights, and delayed parturition) occurred in rats that received oral doses approximately 10 or more times the MRHD (mg/m² basis). No functional or behavioral toxicity was observed in rat offspring. When pregnant rats received pioglitazone during late gestation and lactation, delayed postnatal development, attributed to decreased body weight, occurred in rat offspring at oral maternal doses approximately 2 or more times the MRHD (mg/m² basis). In rabbits, embryotoxicity occurred at oral doses approximately 40 times the MRHD (mg/m² basis).

Metformin Hydrochloride

Metformin was not teratogenic in rats and rabbits at doses up to 600 mg/kg/day. This represents an exposure of about two and six times a human daily dose of 2000 mg based on body surface area comparisons for rats and rabbits, respectively. However, because animal reproduction studies are not always predictive of human response, metformin should not be used during pregnancy unless clearly needed.

Undesirable effects

The following serious adverse reactions are discussed elsewhere in the labeling:

  • Congestive heart failure
  • Lactic acidosis
  • Edema
  • Fractures

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Pioglitazone

Over 8500 patients with type 2 diabetes have been treated with pioglitazone in randomized, double-blind, controlled clinical trials, including 2605 patients with type 2 diabetes and macrovascular disease treated with pioglitazone from the PROactive clinical trial. In these trials, over 6000 patients have been treated with pioglitazone for six months or longer, over 4500 patients have been treated with pioglitazone for one year or longer, and over 3000 patients have been treated with pioglitazone for at least two years.

In six pooled 16-to 26-week placebo-controlled monotherapy and 16-to 24-week add-on combination therapy trials, the incidence of withdrawals due to adverse events was 4.5% for patients treated with pioglitazone and 5.8% for comparator-treated patients.

The most common adverse events leading to withdrawal were related to inadequate glycemic control, although the incidence of these events was lower (1.5%) with pioglitazone than with placebo (3.0%).

In the PROactive trial, the incidence of withdrawals due to adverse events was 9.0% for patients treated with pioglitazone and 7.7% for placebo-treated patients. Congestive heart failure was the most common serious adverse event leading to withdrawal occurring in 1.3% of patients treated with pioglitazone and 0.6% of patients treated with placebo.

Common Adverse Events: 16-to 26-Week Monotherapy Trials

A summary of the incidence and type of common adverse events reported in three pooled 16-to 26-week placebo-controlled monotherapy trials of pioglitazone is provided in Table 1. Terms that are reported represent those that occurred at an incidence of > 5% and more commonly in patients treated with pioglitazone than in patients who received placebo. None of these adverse events were related to the pioglitazone dose.

Table 1: Three Pooled 16-to 26-Week Placebo-Controlled Clinical Trials of Pioglitazone Monotherapy: Adverse Events Reported at an Incidence > 5% and More Commonly in Patients Treated with Pioglitazone than in Patients Treated with Placebo

  % of Patients
Placebo
N=259
Pioglitazone
N=606
Upper Respiratory Tract Infection 8.5 13.2
Headache 6.9 9.1
Sinusitis 4.6 6.3
Myalgia 2.7 5.4
Pharyngitis 0.8 5.1

Common Adverse Events: 16-to 24-Week Add-on Combination Therapy Trials

A summary of the overall incidence and types of common adverse events reported in trials of pioglitazone add-on to metformin is provided in Table 2. Terms that are reported represent those that occurred at an incidence of > 5% and more commonly with the highest tested dose of pioglitazone.

Table 2: 16-to 24-Week Clinical Trials of Pioglitazone Add-on to Metformin

  16-Week Placebo-Controlled Trial Adverse Events Reported in > 5% of Patients and More Commonly in Patients Treated with Pioglitazone + Metformin than in Patients Treated with Placebo + Metformin
% of Patients
Placebo + Metformin
N=160
Pioglitazone 30 mg + Metformin
N=168
Edema 2.5 6.0
Headache 1.9 6.0
  24-Week Non-Controlled Double-Blind Trial Adverse Events Reported in > 5% of Patients and More Commonly in Patients Treated with Pioglitazone 45 mg + Metformin than in Patients Treated with Pioglitazone 30 mg + Metformin
% of Patients
Pioglitazone 30 mg + Metformin
N=411
Pioglitazone 45 mg + Metformin
N=416
Upper Respiratory Tract Infection 12.4 13.5
Edema 5.8 13.9
Headache 5.4 5.8
Weight Increased 2.9 6.7
Note: The preferred terms of edema peripheral, generalized edema, pitting edema, and fluid retention were combined to form the aggregate term of “edema.”

Common Adverse Events: 24-Week ACTOPLUS MET Clinical Trial

Table 3 summarizes the incidence and types of adverse reactions reported in a controlled, 24-week double-blind clinical trial of ACTOPLUS MET dosed twice daily in patients with inadequate glycemic control on diet and exercise (N=600).

Table 3: Adverse Events ( ≥ 5% for ACTOPLUS MET) Reported by Patients with Inadequate Glycemic Control on Diet and Exercise in a 24-Week Double-Blind Clinical Trial of ACTOPLUS MET Administered Twice Daily

% of Patients
  ACTOPLUS MET 15/850 mg Twice Daily
N=201
Pioglitazone 15 mg Twice Daily
N=190
Metformin 850 mg Twice Daily
N=209
Diarrhea 9.0 2.6 15.3
Headache 5.5 2.6 4.8

In this 24-week trial, abdominal pain was reported in 2.0% of patients in the ACTOPLUS MET group, 1.6% in the pioglitazone monotherapy group and 3.3% in the metformin monotherapy group.

Common Adverse Events: PROactive Trial

A summary of the overall incidence and types of common adverse events reported in the PROactive trial is provided in Table 4. Terms that are reported represent those that occurred at an incidence of > 5% and more commonly in patients treated with pioglitazone than in patients who received placebo.

Table 4: PROactive Trial: Incidence and Types of Adverse Events Reported in > 5% of Patients Treated with Pioglitazone and More Commonly than Placebo

  % of Patients
Placebo
N=2633
Pioglitazone
N=2605
Hypoglycemia 18.8 27.3
Edema 15.3 26.7
Cardiac Failure 6.1 8.1
Pain in Extremity 5.7 6.4
Back Pain 5.1 5.5
Chest Pain 5.0 5.1

Mean duration of patient follow-up was 34.5 months.

Congestive Heart Failure

A summary of the incidence of adverse events related to congestive heart failure is provided in Table 5 for the 16-to 24-week add-on to metformin trials. None of the events were fatal.

Table 5: Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) Patients Treated with Pioglitazone or Placebo Added on to Metformin

  Number (%) of Patients
Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks)
Placebo + Metformin
N=160
Pioglitazone 30 mg + Metformin
N=168
Pioglitazone 30 mg + Metformin
N=411
Pioglitazone 45 mg + Metformin
N=416
At least one congestive heart failure event 0 1 (0.6%) 0 1 (0.2%)
Hospitalized 0 1 (0.6%) 0 1 (0.2%)

Table 6: Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF)

Patients Treated with Pioglitazone or Placebo Added on to a Sulfonylurea
  Number (%) of Patients
Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks)
Placebo + Sulfonylurea
N=187
Pioglitazone 15 mg + Sulfonylurea
N=184
Pioglitazone 30 mg + Sulfonylurea
N=189
Pioglitazone 30 mg + Sulfonylurea
N=351
Pioglitazone 45 mg + Sulfonylurea
N=351
At least one congestive heart failure event 2 (1.1%) 0 0 1 (0.3%) 6 (1.7%)
Hospitalized 2 (1.1%) 0 0 0 2 (0.6%)
Patients Treated with Pioglitazone or Placebo Added on to Insulin
  Number (%) of Patients
Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks)
Placebo + Insulin N=187 Pioglitazone 15 mg + Insulin N=191 Pioglitazone 30 mg + Insulin N=188 Pioglitazone 30 mg + Insulin N=345 Pioglitazone 45 mg + Insulin N=345
At least one congestive heart failure event 0 2 (1.0%) 2 (1.1%) 3 (0.9%) 5 (1.4%)
Hospitalized 0 2 (1.0%) 1 (0.5%) 1 (0.3%) 3 (0.9%)
Patients Treated with Pioglitazone or Placebo Added on to Metformin
  Number (%) of Patients
Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks)
Placebo + Metformin N=160 Pioglitazone 30 mg + Metformin N=168 Pioglitazone 30 mg + Metformin N=411 Pioglitazone 45 mg + Metformin N=416
At least one congestive heart failure event 0 1 (0.6%) 0 1 (0.2%)
Hospitalized 0 1 (0.6%) 0 1 (0.2%)

Table 7: Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) in Patients with NYHA Class II or III Congestive Heart Failure Treated with Pioglitazone or Glyburide

  Number (%) of Subjects
Pioglitazone
N=262
Glyburide
N=256
Death due to cardiovascular causes (adjudicated) 5 (1.9%) 6 (2.3%)
Overnight hospitalization for worsening CHF (adjudicated) 26 (9.9%) 12 (4.7%)
Emergency room visit for CHF (adjudicated) 4 (1.5%) 3 (1.2%)
Patients experiencing CHF progression during study 35 (13.4%) 21 (8.2%)

Congestive heart failure events leading to hospitalization that occurred during the PROactive trial are summarized in Table 8.

Table 8: Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) in PROactive Trial

  Number (%) of Patients
Placebo
N=2633
Pioglitazone
N=2605
At least one hospitalized congestive heart failure event 108 (4.1%) 149 (5.7%)
Fatal 22 (0.8%) 25 (1.0%)
Hospitalized, nonfatal 86 (3.3%) 124 (4.7%)

Cardiovascular Safety

In the PROactive trial, 5238 patients with type 2 diabetes and a history of macrovascular disease were randomized to pioglitazone (N=2605), force-titrated up to 45 mg daily or placebo (N=2633) in addition to standard of care. Almost all patients (95%) were receiving cardiovascular medications (beta blockers, ACE inhibitors, angiotensin II receptor blockers, calcium channel blockers, nitrates, diuretics, aspirin, statins, and fibrates). At baseline, patients had a mean age of 62 years, mean duration of diabetes of 9.5 years, and mean HbA1c of 8.1%. Mean duration of follow-up was 34.5 months.

The primary objective of this trial was to examine the effect of pioglitazone on mortality and macrovascular morbidity in patients with type 2 diabetes mellitus who were at high risk for macrovascular events. The primary efficacy variable was the time to the first occurrence of any event in a cardiovascular composite endpoint that included all-cause mortality, nonfatal myocardial infarction (MI) including silent MI, stroke, acute coronary syndrome, cardiac intervention including coronary artery bypass grafting or percutaneous intervention, major leg amputation above the ankle, and bypass surgery or revascularization in the leg. A total of 514 (19.7%) patients treated with pioglitazone and 572 (21.7%) placebo-treated patients experienced at least one event from the primary composite endpoint (HR 0.90; 95% CI: 0.80, 1.02; p=0.10).

Although there was no statistically significant difference between pioglitazone and placebo for the three-year incidence of a first event within this composite, there was no increase in mortality or in total macrovascular events with pioglitazone. The number of first occurrences and total individual events contributing to the primary composite endpoint is shown in Table 9.

Table 9: PROactive Trial: Number of First and Total Events for Each Component Within the Cardiovascular Composite Endpoint

Cardiovascular Events Placebo
N=2633
Pioglitazone
N=2605
First Events n (%) Total events n First Events n (%) Total events n
Any event 572 (21.7) 900 514 (19.7) 803
  All-cause mortality 122 (4.6) 186 110 (4.2) 177
  Nonfatal myocardial infarction (MI) 118 (4.5) 157 105 (4.0) 131
  Stroke 96 (3.6) 119 76 (2.9) 92
  Acute coronary syndrome 63 (2.4) 78 42 (1.6) 65
  Cardiac intervention (CABG/PCI) 101 (3.8) 240 101 (3.9) 195
  Major leg amputation 15 (0.6) 28 9 (0.3) 28
  Leg revascularization 57 (2.2) 92 71 (2.7) 115
CABG = coronary artery bypass grafting; PCI = percutaneous intervention

Weight Gain

Dose-related weight gain occurs when pioglitazone is used alone or in combination with other antidiabetic medications. The mechanism of weight gain is unclear but probably involves a combination of fluid retention and fat accumulation.

Tables 10, 11, and 12 summarize the changes in body weight with pioglitazone and placebo in the 16-to 26-week randomized, double-blind monotherapy and 16-to 24-week combination add-on therapy trials, the PROactive trial, and the 24-week ACTOPLUS MET trial.

Table 10: Weight Changes (kg) from Baseline During Randomized, Double-Blind Clinical Trials

    Control Group (Placebo) Pioglitazone 15 mg Pioglitazone 30 mg
Median (25th, 75th percentile) Median (25th, 75th percentile) Median (25th, 75th percentile)
Monotherapy (16 to 26 weeks)   -1.4 (-2.7, 0.0) N=256 0.9 (-0.5, 3.4) N=79 1.0 (-0.9, 3.4) N=188
Combination Therapy (16 to 24 weeks) Sulfonylurea -0.5 (-1.8, 0.7) N=187 2.0 (0.2, 3.2) N=183 3.1 (1.1, 5.4) N=528
Metformin -1.4 (-3.2, 0.3) N=160 N/A 0.9 (-1.3, 3.2) N=567
Insulin 0.2 (-1.4, 1.4) N=182 2.3 (0.5, 4.3) N=190 3.3 (0.9, 6.3) N=522

Table 11: Median Change in Body Weight in Patients Treated with Pioglitazone Versus Patients Treated with Placebo During the Double-Blind Treatment Period in the PROactive Trial

  Placebo Pioglitazone
Median (25th, 75th percentile) Median (25th, 75th percentile)
Change from baseline to final visit (kg) -0.5 (-3.3, 2.0) N=2581 +3.6 (0.0, 7.5) N=2560
Note: Median exposure for both pioglitazone and placebo was 2.7 years.

Table 12: Weight Changes (kg) from Baseline During Double-Blind Clinical Trial with ACTOPLUS MET in Patients with Inadequate Glycemic Control on Diet and Exercise

  ACTOPLUS MET 15/850 mg Twice Daily Pioglitazone 15 mg Twice Daily Metformin 850 mg Twice Daily
Median (25th , 75th percentile) Median (25th , 75th percentile) Median (25th , 75th percentile)
Change from baseline to final visit (kg) 1.00 (-1.0, 3.0) N=198 1.35 (-0.7, 4.1) N=178 -1.00 (-2.6, 0.4) N=203
Note: Trial duration of 24 weeks.

Edema

Edema induced from taking pioglitazone is reversible when pioglitazone is discontinued. The edema usually does not require hospitalization unless there is coexisting congestive heart failure.

In the 24-week ACTOPLUS MET trial, edema was reported in 3.0% of patients in the ACTOPLUS MET group, 4.2% in the pioglitazone monotherapy group, and 1.4% in the metformin monotherapy group.

A summary of the frequency and types of edema adverse events occurring in clinical investigations of pioglitazone is provided in Table 13.

Table 13: Adverse Events of Edema in Patients Treated with Pioglitazone

    Number (%) of Patients
Placebo Pioglitazone 15 mg Pioglitazone 30 mg
Monotherapy (16 to 26 weeks)   3 (1.2%) N=259 2 (2.5%) N= 81 13 (4.7%) N= 275
Combined Therapy (16 to 24 weeks) Sulfonylurea 4 (2.1%) N=187 3 (1.6%) N=184 61 (11.3%) N=540
Metformin 4 (2.5%) N=160 N/A 34 (5.9%) N=579
Insulin 13 (7.0%) N=187 24 (12.6%) N=191 109 (20.5%) N=533
Note: The preferred terms of edema peripheral, generalized edema, pitting edema, and fluid retention were combined to form the aggregate term of “edema.”

Table 14: Adverse Events of Edema in Patients in the PROactive Trial

Number (%) of Patients
Placebo
N=2633
Pioglitazone
N=2605
419 (15.9%) 712 (27.3%)
Note: The preferred terms of edema peripheral, generalized edema, pitting edema, and fluid retention were combined to form the aggregate term of “edema.”

Hepatic Effects

There has been no evidence of pioglitazone-induced hepatotoxicity in the pioglitazone controlled clinical trial database to date. One randomized, double-blind, three-year trial comparing pioglitazone to glyburide as add-on to metformin and insulin therapy was specifically designed to evaluate the incidence of serum ALT elevation to greater than three times the upper limit of the reference range, measured every eight weeks for the first 48 weeks of the trial then every 12 weeks thereafter. A total of 3/1051 (0.3%) patients treated with pioglitazone and 9/1046 (0.9%) patients treated with glyburide developed ALT values greater than three times the upper limit of the reference range. None of the patients treated with pioglitazone in the pioglitazone controlled clinical trial database to date have had a serum ALT greater than three times the upper limit of the reference range and a corresponding total bilirubin greater than two times the upper limit of the reference range, a combination predictive of the potential for severe drug-induced liver injury.

Hypoglycemia

In the pioglitazone clinical trials, adverse events of hypoglycemia were reported based on clinical judgment of the investigators and did not require confirmation with fingerstick glucose testing.

In the 16-week add-on to sulfonylurea trial, the incidence of reported hypoglycemia was 3.7% with pioglitazone 30 mg and 0.5% with placebo. In the 16-week add-on to insulin trial, the incidence of reported hypoglycemia was 7.9% with pioglitazone 15 mg, 15.4% with pioglitazone 30 mg, and 4.8% with placebo.

The incidence of reported hypoglycemia was higher with pioglitazone 45 mg compared to pioglitazone 30 mg in both the 24-week add-on to sulfonylurea trial (15.7% versus 13.4%) and in the 24-week add-on to insulin trial (47.8% versus 43.5%).

Three patients in these four trials were hospitalized due to hypoglycemia. All three patients were receiving pioglitazone 30 mg (0.9%) in the 24-week add-on to insulin trial. An additional 14 patients reported severe hypoglycemia (defined as causing considerable interference with patient's usual activities) that did not require hospitalization. These patients were receiving pioglitazone 45 mg in combination with sulfonylurea (n=2) or pioglitazone 30 mg or 45 mg in combination with insulin (n=12).

Urinary Bladder Tumors

Tumors were observed in the urinary bladder of male rats in the two-year carcinogenicity study. In two 3-year trials in which pioglitazone was compared to placebo or glyburide, there were 16/3656 (0.44%) reports of bladder cancer in patients taking pioglitazone compared to 5/3679 (0.14%) in patients not taking pioglitazone. After excluding patients in whom exposure to study drug was less than one year at the time of diagnosis of bladder cancer, there were six (0.16%) cases on pioglitazone and two (0.05%) cases on placebo. There are too few events of bladder cancer to establish causality.

Metformin Hydrochloride

In a double-blind clinical study of metformin in patients with type 2 diabetes, a total of 141 patients received metformin therapy (up to 2550 mg per day) and 145 patients received placebo. Adverse reactions reported in greater than 5% of the metformin patients, and that were more common in metformin than placebo-treated patients, are listed in Table 15. In this trial, diarrhea led to discontinuation of study medication in 6% of patients treated with metformin.

Table 15: Most Common Adverse Reactions ( > 5.0%) in a Placebo-Controlled Clinical Study of Metformin Monotherapy*

Adverse Reaction Metformin Monotherapy
(n=141)
Placebo
(n=145)
% of Patients
Diarrhea 53.2 11.7
Nausea/Vomiting 25.5 8.3
Flatulence 12.1 5.5
Asthenia 9.2 5.5
Indigestion 7.1 4.1
Abdominal Discomfort 6.4 4.8
Headache 5.7 4.8
*Reactions that were more common in metformin than placebo-treated patients.

Laboratory Abnormalities

Hematologic Effects

Pioglitazone may cause decreases in hemoglobin and hematocrit. In placebo-controlled monotherapy trials, mean hemoglobin values declined by 2% to 4% in patients treated with pioglitazone compared with a mean change in hemoglobin of -1% to +1% in placebo-treated patients. These changes primarily occurred within the first four to 12 weeks of therapy and remained relatively constant thereafter. These changes may be related to increased plasma volume associated with pioglitazone therapy and are not likely to be associated with any clinically significant hematologic effects.

Vitamin B12 Concentrations

Metformin may lower serum vitamin B12 concentrations. Measurement of hematologic parameters on an annual basis is advised in patients on ACTOPLUS MET and any apparent abnormalities should be appropriately investigated and managed.

Creatine Phosphokinase

During protocol-specified measurement of serum creatine phosphokinase (CPK) in pioglitazone clinical trials, an isolated elevation in CPK to greater than 10 times the upper limit of the reference range was noted in nine (0.2%) patients treated with pioglitazone (values of 2150 to 11400 IU/L) and in no comparator-treated patients. Six of these nine patients continued to receive pioglitazone, two patients were noted to have the CPK elevation on the last day of dosing, and one patient discontinued pioglitazone due to the elevation. These elevations resolved without any apparent clinical sequelae. The relationship of these events to pioglitazone therapy is unknown.

Postmarketing Experience

Pioglitazone

The following adverse reactions have been identified during post-approval use of pioglitazone. Because these reactions are reported voluntarily from a population of uncertain size, it is generally not possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

  • New onset or worsening diabetic macular edema with decreased visual acuity.
  • Fatal and nonfatal hepatic failure.

Postmarketing reports of congestive heart failure have been reported in patients treated with pioglitazone, both with and without previously known heart disease and both with and without concomitant insulin administration.

In postmarketing experience, there have been reports of unusually rapid increases in weight and increases in excess of that generally observed in clinical trials. Patients who experience such increases should be assessed for fluid accumulation and volume-related events such as excessive edema and congestive heart failure.

Overdose

Pioglitazone

During controlled clinical trials, one case of overdose with pioglitazone was reported. A male patient took 120 mg per day for four days, then 180 mg per day for seven days. The patient denied any clinical symptoms during this period.

In the event of overdosage, appropriate supportive treatment should be initiated according to the patient's clinical signs and symptoms.

Metformin Hydrochloride

Overdose of metformin hydrochloride has occurred, including ingestion of amounts greater than 50 grams. Hypoglycemia was reported in approximately 10% of cases, but no causal association with metformin hydrochloride has been established. Lactic acidosis has been reported in approximately 32% of metformin overdose cases. Metformin is dialyzable with a clearance of up to 170 mL/min under good hemodynamic conditions. Therefore, hemodialysis may be useful for removal of accumulated metformin from patients in whom metformin overdosage is suspected.

Pharmacodynamic properties

Pioglitazone

Clinical studies demonstrate that pioglitazone improves insulin sensitivity in insulin-resistant patients. Pioglitazone enhances cellular responsiveness to insulin, increases insulin-dependent glucose disposal and improves hepatic sensitivity to insulin. In patients with type 2 diabetes, the decreased insulin resistance produced by pioglitazone results in lower plasma glucose concentrations, lower plasma insulin concentrations, and lower HbA1c values. In controlled clinical trials, pioglitazone had an additive effect on glycemic control when used in combination with a sulfonylurea, metformin, or insulin.

Patients with lipid abnormalities were included in clinical trials with pioglitazone. Overall, patients treated with pioglitazone had mean decreases in serum triglycerides, mean increases in HDL cholesterol, and no consistent mean changes in LDL and total cholesterol. There is no conclusive evidence of macrovascular benefit with pioglitazone or any other antidiabetic medication.

In a 26-week, placebo-controlled, dose-ranging monotherapy study, mean serum triglycerides decreased in the 15-mg, 30-mg, and 45-mg pioglitazone dose groups compared to a mean increase in the placebo group. Mean HDL cholesterol increased to a greater extent in patients treated with pioglitazone than in the placebo-treated patients. There were no consistent differences for LDL and total cholesterol in patients treated with pioglitazone compared to placebo (see Table 16).

Table 16: Lipids in a 26-Week Placebo-Controlled Monotherapy Dose-Ranging Study

  Placebo Pioglitazone 15 mg Once Daily Pioglitazone 30 mg Once Daily Pioglitazone 45 mg Once Daily
Triglycerides (mg/dL) N=79 N=79 N=84 N=77
Baseline (mean) 263 284 261 260
Percent change from baseline (adjusted mean*) 4.8% -9.0%† -9.6%† -9.3%†
HDL Cholesterol (mg/dL) N=79 N=79 N=83 N=77
Baseline (mean) 42 40 41 41
Percent change from baseline (adjusted mean*) 8.1% 14.1%† 12.2% 19.1%†
LDL Cholesterol (mg/dL) N=65 N=63 N=74 N=62
Baseline (mean) 139 132 136 127
Percent change from baseline (adjusted mean*) 4.8% 7.2% 5.2% 6.0%
Total Cholesterol (mg/dL) N=79 N=79 N=84 N=77
Baseline (mean) 225 220 223 214
Percent change from baseline (adjusted mean*) 4.4% 4.6% 3.3% 6.4%
*Adjusted for baseline, pooled center, and pooled center by treatment interaction
†p < 0.05 versus placebo

In the two other monotherapy studies (16 weeks and 24 weeks) and in combination therapy studies with metformin (16 weeks and 24 weeks), the results were generally consistent with the data above.

Pharmacokinetic properties

Absorption

ACTOPLUS MET

In bioequivalence studies of ACTOPLUS MET 15 mg/500 mg and 15 mg/850 mg, the area under the curve (AUC) and maximum concentration (Cmax) of both the pioglitazone and the metformin component following a single dose of the combination tablet were bioequivalent to ACTOS 15 mg concomitantly administered with Glucophage (500 mg or 850 mg respectively) tablets under fasted conditions in healthy subjects.

Administration of ACTOPLUS MET 15 mg/850 mg with food resulted in no change in overall exposure of pioglitazone. With metformin there was no change in AUC; however, mean peak serum concentration of metformin was decreased by 28% when administered with food. A delayed time to peak serum concentration was observed for both components (1.9 hours for pioglitazone and 0.8 hours for metformin) under fed conditions. These changes are not likely to be clinically significant.

Pioglitazone

Following once-daily administration of pioglitazone, steady-state serum concentrations of both pioglitazone and its major active metabolites, M-III (keto derivative of pioglitazone) and M-IV (hydroxyl derivative of pioglitazone), are achieved within seven days. At steady-state, M-III and M-IV reach serum concentrations equal to or greater than that of pioglitazone. At steady-state, in both healthy volunteers and patients with type 2 diabetes, pioglitazone comprises approximately 30% to 50% of the peak total pioglitazone serum concentrations (pioglitazone plus active metabolites) and 20% to 25% of the total AUC.

Cmax, AUC, and trough serum concentrations (Cmin) for pioglitazone and M-III and M-IV, increased proportionally with administered doses of 15 mg and 30 mg per day.

Following oral administration of pioglitazone, Tmax of pioglitazone was within two hours. Food delays the Tmax to three to four hours, but does not alter the extent of absorption (AUC).

Metformin Hydrochloride

The absolute bioavailability of a 500 mg metformin tablet given under fasting conditions is approximately 50% -60%. Studies using single oral doses of metformin tablets of 500 mg to 1500 mg, and 850 mg to 2550 mg, indicate that there is a lack of dose proportionality with increasing doses, which is due to decreased absorption rather than an alteration in elimination. At usual clinical doses and dosing schedules of metformin, steady-state plasma concentrations of metformin are reached within 24 to 48 hours and are generally < 1 mcg/mL. During controlled clinical trials, maximum metformin plasma levels did not exceed 5 mcg/mL, even at maximum doses.

Food decreases the rate and extent of metformin absorption, as shown by a 40% lower mean Cmax, a 25% lower AUC, and a 35-minute prolongation of Tmax following administration of a single 850 mg tablet of metformin with food, compared to the same tablet strength administered fasting. The clinical relevance of these decreases is unknown.

Distribution

Pioglitazone

The mean apparent volume of distribution (Vd/F) of pioglitazone following single-dose administration is 0.63 ± 0.41 (mean ± SD) L/kg of body weight. Pioglitazone is extensively protein bound ( > 99%) in human serum, principally to serum albumin. Pioglitazone also binds to other serum proteins, but with lower affinity. M-III and M-IV are also extensively bound ( > 98%) to serum albumin.

Metformin Hydrochloride

The Vd/F of metformin following single oral doses of 850 mg immediate-release metformin averaged 654 ± 358 L. Metformin is negligibly bound to plasma proteins. Metformin partitions into erythrocytes, most likely as a function of time.

Metabolism

Pioglitazone

Pioglitazone is extensively metabolized by hydroxylation and oxidation; the metabolites also partly convert to glucuronide or sulfate conjugates. Metabolites M-III and M-IV are the major circulating active metabolites in humans.

In vitro data demonstrate that multiple CYP isoforms are involved in the metabolism of pioglitazone which include CYP2C8 and, to a lesser degree, CYP3A4 with additional contributions from a variety of other isoforms, including the mainly extrahepatic CYP1A1. In vivo study of pioglitazone in combination with gemfibrozil, a strong CYP2C8 inhibitor, showed that pioglitazone is a CYP2C8 substrate. Urinary 6ß-hydroxycortisol/cortisol ratios measured in patients treated with pioglitazone showed that pioglitazone is not a strong CYP3A4 enzyme inducer.

Metformin Hydrochloride

Intravenous single-dose studies in healthy subjects demonstrate that metformin is excreted unchanged in the urine and does not undergo hepatic metabolism (no metabolites have been identified in humans) nor biliary excretion.

Excretion And Elimination

Pioglitazone

Following oral administration, approximately 15% to 30% of the pioglitazone dose is recovered in the urine. Renal elimination of pioglitazone is negligible and the drug is excreted primarily as metabolites and their conjugates. It is presumed that most of the oral dose is excreted into the bile either unchanged or as metabolites and eliminated in the feces.

The mean serum half-life (t½) of pioglitazone and its metabolites (M-III and M-IV) range from three to seven hours and 16 to 24 hours, respectively. Pioglitazone has an apparent clearance, CL/F, calculated to be five to seven L/hr.

Metformin Hydrochloride

Renal clearance is approximately 3.5 times greater than creatinine clearance (CLcr), which indicates that tubular secretion is the major route of metformin elimination. Following oral administration, approximately 90% of the absorbed drug is eliminated via the renal route within the first 24 hours, with a plasma elimination t½ of approximately 6.2 hours. In blood, the elimination t½ is approximately 17.6 hours, suggesting that the erythrocyte mass may be a compartment of distribution.

Date of revision of the text

Jul 2014
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