Zestat

Therapy with lipid-altering agents should be only one component of multiple risk factor intervention in individuals at significantly increased risk for atherosclerotic vascular disease due to hypercholesterolemia. Drug therapy is indicated as an adjunct to diet when the response to a diet restricted in saturated fat and cholesterol and other nonpharmacologic measures alone has been inadequate.

Primary Hyperlipidemia

Zestat^® is indicated for the reduction of elevated total cholesterol (total-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (Apo B), triglycerides (TG), and non-high-density lipoprotein cholesterol (non-HDL-C), and to increase high-density lipoprotein cholesterol (HDL-C) in patients with primary (heterozygous familial and non-familial) hyperlipidemia or mixed hyperlipidemia.

Homozygous Familial Hypercholesterolemia (HoFH)

Zestat is indicated for the reduction of elevated total-C and LDL-C in patients with homozygous familial hypercholesterolemia, as an adjunct to other lipid-lowering treatments (e.g., LDL apheresis) or if such treatments are unavailable.

Limitations Of Use

No incremental benefit of Zestat on cardiovascular morbidity and mortality over and above that demonstrated for atorvastatin has been established. Zestat has not been studied in Fredrickson type I, III, IV, and V dyslipidemias.

Recommended Dosing

The dosage range of Zestat is 10/10 mg/day to 10/80 mg/day. The recommended starting dose of Zestat is 10/10 mg/day or 10/20 mg/day. Zestat can be administered as a single dose at any time of the day, with or without food. The recommended starting dose for patients who require a larger reduction in LDL-C (greater than 55%) is 10/40 mg/day. After initiation and/or upon titration of Zestat, lipid levels should be analyzed within 2 or more weeks and dosage adjusted accordingly.

Patients should swallow Zestat tablets whole. Tablets should not be crushed, dissolved, or chewed.

Patients With Homozygous Familial Hypercholesterolemia

The dosage of Zestat in patients with homozygous familial hypercholesterolemia is 10/40 mg/day or 10/80 mg/day. Zestat should be used as an adjunct to other lipid-lowering treatments (e.g., LDL apheresis) in these patients or if such treatments are unavailable.

Coadministration With Other Drugs

Bile Acid Sequestrants

Dosing of Zestat should occur either greater than or equal to 2 hours before or greater than or equal to 4 hours after administration of a bile acid sequestrant.

Cyclosporine, Clarithromycin, Itraconazole, Or Certain HIV/HCV Antiviral Agents

In patients taking cyclosporine or the HIV protease inhibitors (tipranavir plus ritonavir) or the hepatitis C protease inhibitor (telaprevir), therapy with Zestat should be avoided. In patients with HIV taking lopinavir plus ritonavir, caution should be used when prescribing Zestat and the lowest dose necessary employed. In patients taking clarithromycin, itraconazole, or in patients with HIV taking a combination of saquinavir plus ritonavir, darunavir plus ritonavir, fosamprenavir, or fosamprenavir plus ritonavir, therapy with Zestat should be limited to 10/20 mg, and appropriate clinical assessment is recommended to ensure that the lowest dose necessary of Zestat is employed. In patients taking hepatitis C antiviral agents containing elbasvir and grazoprevir, therapy with Zestat should not exceed 10/20 mg. In patients taking the HIV protease inhibitor nelfinavir or the hepatitis C protease inhibitor boceprevir, therapy with Zestat should be limited to 10/40 mg, and appropriate clinical assessment is recommended to ensure that the lowest dose necessary of Zestat is employed.

Other Concomitant Lipid-Lowering Therapy

The combination of Zestat and gemfibrozil is not recommended.

Active liver disease or unexplained persistent elevations of hepatic transaminase levels.

Hypersensitivity to any component of Zestat.

Women who are pregnant or may become pregnant. Zestat may cause fetal harm when administered to a pregnant woman. Serum cholesterol and triglycerides increase during normal pregnancy, and cholesterol or cholesterol derivatives are essential for fetal development. Atherosclerosis is a chronic process and discontinuation of lipid-lowering drugs during pregnancy should have little impact on the outcome of long-term therapy of primary hypercholesterolemia. There are no adequate and well-controlled studies of Zestat use during pregnancy; however in rare reports, congenital anomalies were observed following intrauterine exposure to statins. In rat and rabbit animal reproduction studies, atorvastatin revealed no evidence of teratogenicity. Zestat should be administered to women of childbearing age only when such patients are highly unlikely to conceive and have been informed of the potential hazards. If the patient becomes pregnant while taking this drug, Zestat should be discontinued immediately, and the patient should be apprised of the potential hazard to the fetus.

Nursing mothers. It is not known whether atorvastatin is excreted into human milk; however, a small amount of another drug in this class does pass into breast milk. Because statins have the potential for serious adverse reactions in nursing infants, women who require Zestat treatment should not breast-feed their infants.

WARNINGS

Included as part of the "PRECAUTIONS" Section

PRECAUTIONS

Myopathy/Rhabdomyolysis

Atorvastatin

Rare cases of rhabdomyolysis with acute renal failure secondary to myoglobinuria have been reported with atorvastatin and with other drugs in this class. A history of renal impairment may be a risk factor for the development of rhabdomyolysis. Such patients merit closer monitoring for skeletal muscle effects.

Atorvastatin, like other statins, occasionally causes myopathy, defined as muscle aches or muscle weakness in conjunction with increases in creatine phosphokinase (CPK) values >10 times upper limit of normal (ULN). The concomitant use of higher doses of atorvastatin with certain drugs such as cyclosporine and strong CYP3A4 inhibitors (e.g., clarithromycin, itraconazole, and HIV protease inhibitors) increases the risk of myopathy/rhabdomyolysis.

There have been rare reports of immune-mediated necrotizing myopathy (IMNM), an autoimmune myopathy, associated with statin use. IMNM is characterized by: proximal muscle weakness and elevated serum creatine kinase, which persist despite discontinuation of statin treatment; muscle biopsy showing necrotizing myopathy without significant inflammation; improvement with immunosuppressive agents.

Myopathy should be considered in any patient with diffuse myalgias, muscle tenderness or weakness, and/or marked elevation of CPK. Patients should be advised to report promptly unexplained muscle pain, tenderness or weakness, particularly if accompanied by malaise or fever or if muscle signs and symptoms persist after discontinuing Zestat. Zestat therapy should be discontinued if markedly elevated CPK levels occur or myopathy is diagnosed or suspected.

The risk of myopathy during treatment with statins is increased with concurrent administration of cyclosporine, fibric acid derivatives, erythromycin, clarithromycin, the hepatitis C antiviral agents telaprevir, a combination of elbasvir plus grazoprevir, combinations of HIV protease inhibitors, including saquinavir plus ritonavir, lopinavir plus ritonavir, tipranavir plus ritonavir, darunavir plus ritonavir, fosamprenavir, and fosamprenavir plus ritonavir, niacin, or azole antifungals. Physicians considering combined therapy with Zestat and fibric acid derivatives, erythromycin, clarithromycin, a combination of elbasvir plus grazoprevir, a combination of saquinavir plus ritonavir, lopinavir plus ritonavir, darunavir plus ritonavir, fosamprenavir, or fosamprenavir plus ritonavir, azole antifungals, or lipid-modifying doses of niacin should carefully weigh the potential benefits and risks and should carefully monitor patients for any signs or symptoms of muscle pain, tenderness, or weakness, particularly during the initial months of therapy and during any periods of upward dosage titration of either drug. Lower starting and maintenance doses of Zestat should be considered when taken concomitantly with the aforementioned drugs. Periodic CPK determinations may be considered in such situations, but there is no assurance that such monitoring will prevent the occurrence of severe myopathy.

Prescribing recommendations for interacting agents are summarized in Table 1.

Table 1: Drug Interactions Associated with Increased Risk of Myopathy/Rhabdomyolysis with Atorvastatin

Cases of myopathy, including rhabdomyolysis, have been reported with atorvastatin coadministered with colchicine, and caution should be exercised when prescribing Zestat with colchicine.

Zestat therapy should be temporarily withheld or discontinued in any patient with an acute, serious condition suggestive of a myopathy or having a risk factor predisposing to the development of renal failure secondary to rhabdomyolysis (e.g., severe acute infection, hypotension, major surgery, trauma, severe metabolic, endocrine and electrolyte disorders, and uncontrolled seizures).

Ezetimibe

In clinical trials, there was no excess of myopathy or rhabdomyolysis associated with ezetimibe compared with the relevant control arm (placebo or statin alone). However, myopathy and rhabdomyolysis are known adverse reactions to statins and other lipid-lowering drugs. In clinical trials, the incidence of creatine phosphokinase (CPK) >10 times ULN was 0.2% for ezetimibe vs. 0.1% for placebo, and 0.1% for ezetimibe coadministered with a statin vs. 0.4% for statins alone. Risk for skeletal muscle toxicity increases with higher doses of statin, advanced age (>65), hypothyroidism, renal impairment, and depending on the statin used, concomitant use of other drugs.

In postmarketing experience with ezetimibe, cases of myopathy and rhabdomyolysis have been reported. Most patients who developed rhabdomyolysis were taking a statin prior to initiating ezetimibe. However, rhabdomyolysis has been reported with ezetimibe monotherapy and with the addition of ezetimibe to agents known to be associated with increased risk of rhabdomyolysis, such as fibric acid derivatives. Zestat and a fenofibrate, if taking concomitantly, should both be immediately discontinued if myopathy is diagnosed or suspected. The presence of muscle symptoms and a CPK level >10 times the ULN indicates myopathy.

Liver Enzymes

Atorvastatin

Statins, like some other lipid-lowering therapies, have been associated with biochemical abnormalities of liver function. Persistent elevations (>3 times ULN occurring on 2 or more occasions) in serum transaminases occurred in 0.7% of patients who received atorvastatin in clinical trials. The incidence of these abnormalities was 0.2%, 0.2%, 0.6%, and 2.3% for 10, 20, 40, and 80 mg atorvastatin, respectively.

One patient in clinical trials of atorvastatin developed jaundice. Increases in liver function tests (LFT) in other patients were not associated with jaundice or other clinical signs or symptoms. Upon dose reduction, drug interruption, or discontinuation, transaminase levels returned to or near pretreatment levels without sequelae. Eighteen of 30 patients with persistent LFT elevations continued treatment with a reduced dose of atorvastatin.

Ezetimibe

In controlled clinical studies, the incidence of consecutive elevations (≥3 times ULN) in hepatic transaminase levels was similar between ezetimibe (0.5%) and placebo (0.3%).

In controlled clinical combination studies of ezetimibe coadministered with atorvastatin, the incidence of consecutive elevations (≥3 times ULN) in hepatic transaminase levels was 0.6% for patients treated with ezetimibe administered with atorvastatin. These elevations in transaminases were generally asymptomatic, not associated with cholestasis, and returned to baseline after discontinuation of therapy or with continued treatment.

Zestat

It is recommended that liver enzyme tests be obtained prior to initiating therapy with Zestat and repeated as clinically indicated. There have been rare postmarketing reports of fatal and non-fatal hepatic failure in patients taking statins, including atorvastatin. If serious liver injury with clinical symptoms and/or hyperbilirubinemia or jaundice occurs during treatment with Zestat, promptly interrupt therapy. If an alternate etiology is not found, do not restart Zestat.

Zestat should be used with caution in patients who consume substantial quantities of alcohol and/or have a history of liver disease. Active liver disease or unexplained persistent transaminase elevations are contraindications to the use of Zestat.

Endocrine Function

Increases in HbA1c and fasting serum glucose levels have been reported with HMG-CoA reductase inhibitors, including atorvastatin.

Statins interfere with cholesterol synthesis and theoretically might blunt adrenal and/or gonadal steroid production. Clinical studies have shown that atorvastatin does not reduce basal plasma cortisol concentration or impair adrenal reserve and that ezetimibe did not impair adrenocortical steroid hormone production. The effects of statins on male fertility have not been studied in adequate numbers of patients. The effects, if any, on the pituitary-gonadal axis in premenopausal women are unknown. Caution should be exercised if Zestat is administered concomitantly with drugs that may decrease the levels or activity of endogenous steroid hormones, such as ketoconazole, spironolactone, and cimetidine.

Use In Patients With Recent Stroke Or TIA

In a post-hoc analysis of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) study where atorvastatin 80 mg vs. placebo was administered in 4,731 subjects without CHD who had a stroke or TIA within the preceding 6 months, a higher incidence of hemorrhagic stroke was seen in the atorvastatin 80 mg group compared to placebo (55, 2.3% atorvastatin vs. 33, 1.4% placebo; HR: 1.68, 95% CI: 1.09, 2.59; p=0.0168). The incidence of fatal hemorrhagic stroke was similar across treatment groups (17 vs. 18 for the atorvastatin and placebo groups, respectively). The incidence of nonfatal hemorrhagic stroke was significantly higher in the atorvastatin (38, 1.6%) group as compared to the placebo group (16, 0.7%). Some baseline characteristics, including hemorrhagic and lacunar stroke on study entry, were associated with a higher incidence of hemorrhagic stroke in the atorvastatin group.

CNS Toxicity

Atorvastatin

Brain hemorrhage was seen in a female dog treated for 3 months at 120 mg/kg/day. Brain hemorrhage and optic nerve vacuolation were seen in another female dog that was sacrificed in moribund condition after 11 weeks of escalating doses up to 280 mg/kg/day. The 120 mg/kg dose resulted in a systemic exposure approximately 16 times the human plasma area-under-the-curve (AUC, 0-24 hours) based on the maximum human dose of 80 mg/day. A single tonic convulsion was seen in each of 2 male dogs (one treated at 10 mg/kg/day and one at 120 mg/kg/day) in a 2-year study. No CNS lesions have been observed in mice after chronic treatment for up to 2 years at doses up to 400 mg/kg/day or in rats at doses up to 100 mg/kg/day. These doses were 6 to 11 times (mouse) and 8 to 16 times (rat) the human AUC(0-24) based on the maximum recommended human dose of 80 mg/day.

CNS vascular lesions, characterized by perivascular hemorrhages, edema, and mononuclear cell infiltration of perivascular spaces, have been observed in dogs treated with other members of this class. A chemically similar drug in this class produced optic nerve degeneration (Wallerian degeneration of retinogeniculate fibers) in clinically normal dogs in a dose-dependent fashion at a dose that produced plasma drug levels about 30 times higher than the mean drug level in humans taking the highest recommended dose.

Patient Counseling Information

Advise the patient to read the FDA-Approved Patient Labeling (PATIENT INFORMATION).

Patients should be advised to adhere to their National Cholesterol Education Program (NCEP)recommended diet, a regular exercise program, and periodic testing of a fasting lipid panel.

Muscle Pain

All patients starting therapy with Zestat should be advised of the risk of myopathy and told to report promptly any unexplained muscle pain, tenderness or weakness particularly if accompanied by malaise or fever or if these muscle signs or symptoms persist after discontinuing Zestat. The risk of this occurring is increased when taking certain types of medication or consuming larger quantities (>1 liter) of grapefruit juice. Patients should discuss all medication, both prescription and over-the-counter, with their physician.

Liver Enzymes

It is recommended that liver enzyme tests be performed before the initiation of Zestat and if signs or symptoms of liver injury occur. All patients treated with Zestat should be advised to report promptly any symptoms that may indicate liver injury, including fatigue, anorexia, right upper abdominal discomfort, dark urine, or jaundice.

Pregnancy

Women of childbearing age should be advised to use an effective method of birth control to prevent pregnancy while using Zestat. Discuss future pregnancy plans with your patients, and discuss when to stop taking Zestat if they are trying to conceive. Patients should be advised that if they become pregnant they should stop taking Zestat and call their healthcare professional.

Breast-Feeding

Women who are breast-feeding should be advised to not use Zestat. Patients who have a lipid disorder and are breast-feeding should be advised to discuss the options with their healthcare professionals.

Important Storage And Administration Instructions

Patients should be advised to see the FDA-Approved Patient Labeling (PATIENT INFORMATION).

Tablets should be swallowed whole. Do not crush, dissolve, or chew tablets.

If a dose is missed, the patient should not take an extra dose. Just resume the usual schedule.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment Of Fertility

No animal carcinogenicity or fertility studies have been conducted with the combination of ezetimibe and atorvastatin. The combination of ezetimibe with atorvastatin did not show evidence of mutagenicity in vitro in a microbial mutagenicity (Ames) test with Salmonella typhimurium and Escherichia coli with or without metabolic activation. No evidence of clastogenicity was observed in vitro in a chromosomal aberration assay in human peripheral blood lymphocytes with ezetimibe and atorvastatin with or without metabolic activation. There was no evidence of genotoxicity at doses up to 250 mg/kg with the combination of ezetimibe and atorvastatin (1:1) in the in vivo mouse micronucleus test.

Ezetimibe

A 104-week dietary carcinogenicity study with ezetimibe was conducted in rats at doses up to 1500 mg/kg/day (males) and 500 mg/kg/day (females) (~20 times the human exposure at 10 mg daily based on AUC0-24hr for total ezetimibe). A 104-week dietary carcinogenicity study with ezetimibe was also conducted in mice at doses up to 500 mg/kg/day (>150 times the human exposure at 10 mg daily based on AUC0-24hr for total ezetimibe). There were no statistically significant increases in tumor incidences in drug-treated rats or mice.

No evidence of mutagenicity was observed in vitro in a microbial mutagenicity (Ames) test with Salmonella typhimurium and Escherichia coli with or without metabolic activation. No evidence of clastogenicity was observed in vitro in a chromosomal aberration assay in human peripheral blood lymphocytes with or without metabolic activation. In addition, there was no evidence of genotoxicity in the in vivo mouse micronucleus test.

In oral (gavage) fertility studies of ezetimibe conducted in rats, there was no evidence of reproductive toxicity at doses up to 1000 mg/kg/day in male or female rats (~7 times the human exposure at 10 mg daily based on AUC0-24hr for total ezetimibe).

Atorvastatin

In a 2-year carcinogenicity study in rats at dose levels of 10, 30, and 100 mg/kg/day, 2 rare tumors were found in muscle in high-dose females: in one, there was a rhabdomyosarcoma and, in another, there was a fibrosarcoma. This dose represents a plasma AUC0-24hr value of approximately 16 times the mean human plasma drug exposure after an 80-mg oral dose.

A 2-year carcinogenicity study in mice given 100, 200, or 400 mg/kg/day resulted in a significant increase in liver adenomas in high-dose males and liver carcinomas in high-dose females. These findings occurred at plasma AUC0-24hr values of approximately 6 times the mean human plasma drug exposure after an 80-mg oral dose.

In vitro, atorvastatin was not mutagenic or clastogenic in the following tests with and without metabolic activation: the Ames test with Salmonella typhimurium and Escherichia coli, the HGPRT forward mutation assay in Chinese hamster lung cells, and the chromosomal aberration assay in Chinese hamster lung cells. Atorvastatin was negative in the in vivo mouse micronucleus test.

Studies in rats performed at doses up to 175 mg/kg (15 times the human exposure) produced no changes in fertility. There was aplasia and aspermia in the epididymis of 2 of 10 rats treated with 100 mg/kg/day of atorvastatin for 3 months (16 times the human AUC at the 80-mg dose); testis weights were significantly lower at 30 and 100 mg/kg and epididymal weight was lower at 100 mg/kg. Male rats given 100 mg/kg/day for 11 weeks prior to mating had decreased sperm motility, spermatid head concentration, and increased abnormal sperm. Atorvastatin caused no adverse effects on semen parameters, or reproductive organ histopathology in dogs given doses of 10, 40, or 120 mg/kg for two years.

Use In Specific Populations

Pregnancy

Pregnancy Category X.

Zestat

Zestat is contraindicated in women who are or may become pregnant. Serum cholesterol and triglycerides increase during normal pregnancy. Lipid-lowering drugs offer no benefit during pregnancy, because cholesterol and cholesterol derivatives are needed for normal fetal development. Atherosclerosis is a chronic process, and discontinuation of lipid-lowering drugs during pregnancy should have little impact on long-term outcomes of primary hypercholesterolemia therapy.

There are no adequate and well-controlled studies of Zestat use during pregnancy. There have been rare reports of congenital anomalies following intrauterine exposure to statins. In a review of about 100 prospectively followed pregnancies in women exposed to other statins, the incidences of congenital anomalies, spontaneous abortions, and fetal deaths/stillbirths did not exceed the rate expected in the general population. However, this study was only able to exclude a three-to-four-fold increased risk of congenital anomalies over background incidence. In 89% of these cases, drug treatment started before pregnancy and stopped during the first trimester when pregnancy was identified.

Statins may cause fetal harm when administered to a pregnant woman. Because Zestat contains atorvastatin, Zestat should be administered to women of childbearing potential only when such patients are highly unlikely to conceive and have been informed of the potential hazards. If the woman becomes pregnant while taking Zestat, it should be discontinued immediately and the patient advised again as to the potential hazards to the fetus and the lack of known clinical benefit with continued use during pregnancy.

Ezetimibe

In oral (gavage) embryo-fetal development studies of ezetimibe conducted in rats and rabbits during organogenesis, there was no evidence of embryolethal effects at the doses tested (250, 500, 1000 mg/kg/day). In rats, increased incidences of common fetal skeletal findings (extra pair of thoracic ribs, unossified cervical vertebral centra, shortened ribs) were observed at 1000 mg/kg/day (~10 times the human exposure at 10 mg daily based on AUC0-24hr for total ezetimibe). In rabbits treated with ezetimibe, an increased incidence of extra thoracic ribs was observed at 1000 mg/kg/day (150 times the human exposure at 10 mg daily based on AUC0-24hr for total ezetimibe). Ezetimibe crossed the placenta when pregnant rats and rabbits were given multiple oral doses.

Multiple-dose studies of ezetimibe given in combination with statins in rats and rabbits during organogenesis result in higher ezetimibe and statin exposures. Reproductive findings occur at lower doses in combination therapy compared to monotherapy.

Atorvastatin

Atorvastatin crosses the rat placenta and reaches a level in fetal liver equivalent to that of maternal plasma. Atorvastatin was not teratogenic in rats at doses up to 300 mg/kg/day or in rabbits at doses up to 100 mg/kg/day. These doses resulted in multiples of about 30 times (rat) or 20 times (rabbit) the human exposure based on surface area (mg/m²).

In a study in rats given 20, 100, or 225 mg/kg/day, from gestation Day 7 through to lactation Day 21 (weaning), there was decreased pup survival at birth, neonate, weaning, and maturity in pups of mothers dosed with 225 mg/kg/day. Body weight was decreased on Days 4 and 21 in pups of mothers dosed at 100 mg/kg/day; pup body weight was decreased at birth and at Days 4, 21, and 91 at 225 mg/kg/day. Pup development was delayed (rotorod performance at 100 mg/kg/day and acoustic startle at 225 mg/kg/day; pinnae detachment and eye opening at 225 mg/kg/day). These doses correspond to 6 times (100 mg/kg) and 22 times (225 mg/kg) the human AUC at 80 mg/day. Rare reports of congenital anomalies have been received following intrauterine exposure to statin reductase inhibitors.

Nursing Mothers

In rat studies, exposure to total ezetimibe in nursing pups was up to half of that observed in maternal plasma. It is not known whether ezetimibe is excreted into human breast milk.

It is not known whether atorvastatin is excreted in human milk, but a small amount of another drug in this class does pass into breast milk. Nursing rat pups had plasma and liver atorvastatin levels of 50% and 40%, respectively, of that in their mother’s milk. Because of the potential for adverse reactions in nursing infants, women taking Zestat should not breast-feed.

Pediatric Use

Zestat

Safety and effectiveness have not been established in pediatric patients.

Ezetimibe

Based on total ezetimibe (ezetimibe + ezetimibe-glucuronide) there are no pharmacokinetic differences between adolescents and adults. Pharmacokinetic data in the pediatric population <10 years of age are not available.

Atorvastatin

Pharmacokinetic data in the pediatric population are not available.

Geriatric Use

Of the patients who received ezetimibe coadministered with atorvastatin in clinical studies, 1166 were 65 and older (this included 291 who were 75 and older). The effectiveness and safety of Zestat were similar between these patients and younger subjects. Greater sensitivity of some older individuals cannot be ruled out. Since advanced age (≥65 years) is a predisposing factor for myopathy, Zestat should be prescribed with caution in the elderly.

In geriatric patients, no dosage adjustment of Zestat is necessary.

Hepatic Impairment

Zestat is contraindicated in patients with active liver disease or unexplained persistent elevations in hepatic transaminase levels.

Renal Impairment

A history of renal impairment may be a risk factor for statin-associated myopathy. These patients merit closer monitoring for skeletal muscle effects.

In patients with renal impairment, no dosage adjustment of Zestat is necessary.

The following serious adverse reactions are discussed in greater detail in other sections of the label:

• Rhabdomyolysis and myopathy
• Liver enzyme abnormalities

Clinical Trials Experience

Zestat

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

In a Zestat (ezetimibe and atorvastatin) placebo-controlled clinical trial, 628 patients (age range 18-86 years, 59% women, 85% Caucasians, 6% Blacks, 5% Hispanics, 3% Asians) with a median treatment duration of 12 weeks, 6% of patients on Zestat and 5% of patients on placebo discontinued due to adverse reactions.

The most common adverse reactions in the group treated with Zestat that led to treatment discontinuation and occurred at a rate greater than placebo were:

• Myalgia (0.8%)
• Abdominal pain (0.8%)
• Increased hepatic enzymes (0.8%)

The most commonly reported adverse reactions (incidence ≥2% and greater than placebo) in this trial were: increased ALT (5%), increased AST (4%), and musculoskeletal pain (4%).

Zestat has been evaluated for safety in 2403 patients in 7 clinical trials (one placebo-controlled trial and six active-controlled trials).

Table 2 summarizes the frequency of clinical adverse reactions reported in ≥2% of patients treated with Zestat (n=255) and at an incidence greater than placebo, regardless of causality assessment, from the placebo-controlled trial.

Table 2*: Clinical and Selected Laboratory Adverse Reactions Occurring in ≥2% of Patients Treated with Zestat and at an Incidence Greater than Placebo, Regardless of Causality

After completing the 12-week study, eligible patients were assigned to coadministered ezetimibe and atorvastatin equivalent to Zestat (10/10-10/80) or atorvastatin (10-80 mg/day) for an additional 48 weeks. The long-term coadministration of ezetimibe plus atorvastatin had an overall safety profile similar to that of atorvastatin alone.

Ezetimibe

In 10 double-blind, placebo-controlled clinical trials, 2396 patients with primary hyperlipidemia (age range 9-86 years, 50% women, 90% Caucasians, 5% Blacks, 3% Hispanics, 2% Asians) and elevated LDL-C were treated with ezetimibe 10 mg/day for a median treatment duration of 12 weeks (range 0 to 39 weeks).

Adverse reactions reported in ≥2% of patients treated with ezetimibe and at an incidence greater than placebo regardless of causality assessment are shown in Table 3.

Table 3: Clinical Adverse Reactions Occurring in ≥2% of Patients Treated with Ezetimibe and at an Incidence Greater than Placebo, Regardless of Causality

Atorvastatin

In an atorvastatin placebo-controlled clinical trial database of 16,066 patients (8755 atorvastatin vs. 7311 placebo; age range 10.93 years, 39% women, 91% Caucasians, 3% Blacks, 2% Asians, 4% other) with a median treatment duration of 53 weeks, 9.7% of patients on atorvastatin and 9.5% of the patients on placebo discontinued due to adverse reactions regardless of causality.

The most commonly reported adverse reactions (incidence ≥2% and greater than placebo) regardless of causality, in patients treated with atorvastatin in placebo controlled trials (n=8755) were: nasopharyngitis (8.3%), arthralgia (6.9%), diarrhea (6.8%), pain in extremity (6.0%), and urinary tract infection (5.7%).

Table 4 summarizes the frequency of clinical adverse reactions, regardless of causality, reported in ≥2% and at a rate greater than placebo in patients treated with atorvastatin (n=8755), from seventeen placebo-controlled trials.

Table 4: Clinical Adverse Reactions Occurring in >2% in Patients Treated with any dose of Atorvastatin and at an Incidence Greater than Placebo Regardless of Causality (% of patients).

Postmarketing Experience

Because the reactions below 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.

The additional events described below have been identified during post-approval use of ezetimibe and/or atorvastatin.

Blood and lymphatic system disorders: thrombocytopenia

Nervous system disorders: headache; dizziness; paresthesia; peripheral neuropathy

There have been rare postmarketing reports of cognitive impairment (e.g., memory loss, forgetfulness, amnesia, memory impairment, confusion) associated with statin use. These cognitive issues have been reported for all statins. The reports are generally nonserious, and reversible upon statin discontinuation, with variable times to symptom onset (1 day to years) and symptom resolution (median of 3 weeks).

Gastrointestinal disorders: pancreatitis

Skin and subcutaneous tissue disorders: angioedema; bullous rashes (including erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis); rash; urticaria

Musculoskeletal and connective tissue disorders: myositis; myopathy/rhabdomyolysis

There have been rare reports of immune-mediated necrotizing myopathy associated with statin use.

Injury, poisoning and procedural complications: tendon rupture

Immune system disorders: anaphylaxis; hypersensitivity reactions

Hepatobiliary disorders: hepatitis; cholelithiasis; cholecystitis; fatal and nonfatal hepatic failure

Psychiatric disorders: depression Respiratory: interstitial lung disease

Laboratory abnormalities: elevated creatine phosphokinase

General disorders and administration site conditions: fatigue

Zestat

No specific treatment of overdosage with Zestat can be recommended. In the event of an overdose, the patient should be treated symptomatically, and supportive measures instituted as required.

Ezetimibe

In clinical studies, administration of ezetimibe, 50 mg/day to 15 healthy subjects for up to 14 days, 40 mg/day to 18 patients with primary hyperlipidemia for up to 56 days, and 40 mg/day to 27 patients with homozygous sitosterolemia for 26 weeks, was generally well tolerated. One female patient with homozygous sitosterolemia took an accidental overdose of ezetimibe 120 mg/day for 28 days with no reported clinical or laboratory adverse events.

Atorvastatin

Due to extensive drug binding to plasma proteins, hemodialysis is not expected to significantly enhance atorvastatin clearance.

Clinical studies have demonstrated that elevated levels of total-C, LDL-C and Apo B, the major protein constituent of LDL, promote human atherosclerosis. In addition, decreased levels of HDL-C are associated with the development of atherosclerosis. Epidemiologic studies have established that cardiovascular morbidity and mortality vary directly with the level of total-C and LDL-C and inversely with the level of HDL-C. Like LDL, cholesterol-enriched triglyceride-rich lipoproteins, including very-low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), and remnants, can also promote atherosclerosis. The independent effect of raising HDL-C or lowering TG on the risk of coronary and cardiovascular morbidity and mortality has not been determined.

Atorvastatin as well as some of its metabolites are pharmacologically active in humans. The liver is the primary site of action and the principal site of cholesterol synthesis and LDL clearance. Drug dosage, rather than systemic drug concentration, correlates better with LDL-C reduction. Individualization of drug dosage should be based on therapeutic response.

Zestat

Zestat has been shown to be bioequivalent to coadministration of corresponding doses of ezetimibe and atorvastatin tablets.

Absorption

Ezetimibe

After oral administration, ezetimibe is absorbed and extensively conjugated to a pharmacologically active phenolic glucuronide (ezetimibe-glucuronide).

Atorvastatin

Maximum plasma atorvastatin concentrations after oral administration occur within 1 to 2 hours. Extent of absorption increases in proportion to atorvastatin dose. The absolute bioavailability of atorvastatin (parent drug) is approximately 14% and the systemic availability of HMG-CoA reductase inhibitory activity is approximately 30%. The low systemic availability is attributed to presystemic clearance in gastrointestinal mucosa and/or hepatic first-pass metabolism. Plasma atorvastatin concentrations are lower (approximately 30% for Cmax and AUC) following evening drug administration compared with morning. However, LDL-C reduction is the same regardless of the time of day of drug administration.

Effect Of Food On Oral Absorption

Zestat

When Zestat 10/80 tablet was administered with a high-fat meal, atorvastatin Cmax decreased by 7% and no effect on atorvastatin AUC was observed. A high-fat meal had no effect on the pharmacokinetics of unconjugated ezetimibe.

Zestat can be taken with or without food.

Distribution

Ezetimibe

Ezetimibe and ezetimibe-glucuronide are highly bound (>90%) to human plasma proteins.

Atorvastatin

Mean volume of distribution of atorvastatin is approximately 381 liters. Atorvastatin is ≥98% bound to plasma proteins. A blood/plasma ratio of approximately 0.25 indicates poor drug penetration into red blood cells. Based on observations in rats, atorvastatin is likely to be secreted in human milk.

Metabolism And Excretion

Ezetimibe

Ezetimibe is primarily metabolized in the small intestine and liver via glucuronide conjugation with subsequent biliary and renal excretion. Minimal oxidative metabolism has been observed in all species evaluated.

In humans, ezetimibe is rapidly metabolized to ezetimibe-glucuronide. Ezetimibe and ezetimibeglucuronide are the major drug-derived compounds detected in plasma, constituting approximately 10 to 20% and 80 to 90% of the total drug in plasma, respectively. Both ezetimibe and ezetimibe-glucuronide are eliminated from plasma with a half-life of approximately 22 hours for both ezetimibe and ezetimibeglucuronide. Plasma concentration-time profiles exhibit multiple peaks, suggesting enterohepatic recycling.

Following oral administration of ¹⁴C-ezetimibe (20 mg) to human subjects, total ezetimibe (ezetimibe + ezetimibe-glucuronide) accounted for approximately 93% of the total radioactivity in plasma. After 48 hours, there were no detectable levels of radioactivity in the plasma.

Approximately 78% and 11% of the administered radioactivity were recovered in the feces and urine, respectively, over a 10-day collection period. Ezetimibe was the major component in feces and accounted for 69% of the administered dose, while ezetimibe-glucuronide was the major component in urine and accounted for 9% of the administered dose.

Atorvastatin

Atorvastatin is extensively metabolized to ortho-and parahydroxylated derivatives and various beta-oxidation products. In vitro inhibition of HMG-CoA reductase by ortho-and parahydroxylated metabolites is equivalent to that of atorvastatin. Approximately 70% of circulating inhibitory activity for HMG-CoA reductase is attributed to active metabolites. In vitro studies suggest the importance of atorvastatin metabolism by cytochrome P450 3A4, consistent with increased plasma concentrations of atorvastatin in humans following coadministration with erythromycin, a known inhibitor of this isozyme. In animals, the ortho-hydroxy metabolite undergoes further glucuronidation.

Atorvastatin and its metabolites are eliminated primarily in bile following hepatic and/or extra-hepatic metabolism; however, the drug does not appear to undergo enterohepatic recirculation. Mean plasma elimination half-life of atorvastatin in humans is approximately 14 hours, but the half-life of inhibitory activity for HMG-CoA reductase is 20 to 30 hours due to the contribution of active metabolites. Less than 2% of a dose of atorvastatin is recovered in urine following oral administration.