Coreg

Dosage And Strengths

The white, oval, film-coated tablets are available in the following strengths:

• 3.125 mg – engraved with “39” and “SB”
• 6.25 mg – engraved with “4140” and “SB”
• 12.5 mg – engraved with “4141” and “SB”
• 25 mg – engraved with “4142” and “SB”

Storage And Handling

The white, oval, film-coated tablets are available in the following strengths:

• 3.125 mg – engraved with “39” and “SB”
• 6.25 mg – engraved with “4140” and “SB”
• 12.5 mg – engraved with “4141” and “SB”
• 25 mg – engraved with “4142” and “SB”

The 6.25-mg, 12.5-mg, and 25-mg tablets are TILTAB tablets.

• 3.125 mg bottles of 100: NDC 0007-4139-20
• 6.25 mg bottles of 100: NDC 0007-4140-20
• 12.5 mg bottles of 100: NDC 0007-4141-20
• 25 mg bottles of 100: NDC 0007-4142-20

Store below 30°C (86°F). Protect from moisture. Dispense in a tight, light-resistant container.

Manufactured for: GlaxoSmithKline Research Triangle Park, NC 27709. Revised: Sep 2017.

Heart Failure

COREG is indicated for the treatment of mild-to-severe chronic heart failure of ischemic or cardiomyopathic origin, usually in addition to diuretics, ACE inhibitors, and digitalis, to increase survival and, also, to reduce the risk of hospitalization.

Left Ventricular Dysfunction Following Myocardial Infarction

COREG is indicated to reduce cardiovascular mortality in clinically stable patients who have survived the acute phase of a myocardial infarction and have a left ventricular ejection fraction of less than or equal to 40% (with or without symptomatic heart failure).

Hypertension

COREG is indicated for the management of essential hypertension. It can be used alone or in combination with other antihypertensive agents, especially thiazide-type diuretics.

COREG should be taken with food to slow the rate of absorption and reduce the incidence of orthostatic effects.

Heart Failure

DOSAGE MUST BE INDIVIDUALIZED AND CLOSELY MONITORED BY A PHYSICIAN DURING UP-TITRATION. Prior to initiation of COREG, it is recommended that fluid retention be minimized. The recommended starting dose of COREG is 3.125 mg twice daily for 2 weeks. If tolerated, patients may have their dose increased to 6.25, 12.5, and 25 mg twice daily over successive intervals of at least 2 weeks. Patients should be maintained on lower doses if higher doses are not tolerated. A maximum dose of 50 mg twice daily has been administered to patients with mild-to-moderate heart failure weighing over 85 kg (187 lbs).

Patients should be advised that initiation of treatment and (to a lesser extent) dosage increases may be associated with transient symptoms of dizziness or lightheadedness (and rarely syncope) within the first hour after dosing. During these periods, patients should avoid situations such as driving or hazardous tasks, where symptoms could result in injury. Vasodilatory symptoms often do not require treatment, but it may be useful to separate the time of dosing of COREG from that of the ACE inhibitor or to reduce temporarily the dose of the ACE inhibitor. The dose of COREG should not be increased until symptoms of worsening heart failure or vasodilation have been stabilized.

Fluid retention (with or without transient worsening heart failure symptoms) should be treated by an increase in the dose of diuretics.

The dose of COREG should be reduced if patients experience bradycardia (heart rate less than 55 beats per minute).

Episodes of dizziness or fluid retention during initiation of COREG can generally be managed without discontinuation of treatment and do not preclude subsequent successful titration of, or a favorable response to, carvedilol.

Left Ventricular Dysfunction Following Myocardial Infarction

DOSAGE MUST BE INDIVIDUALIZED AND MONITORED DURING UP-TITRATION. Treatment with COREG may be started as an inpatient or outpatient and should be started after the patient is hemodynamically stable and fluid retention has been minimized. It is recommended that COREG be started at 6.25 mg twice daily and increased after 3 to 10 days, based on tolerability, to 12.5 mg twice daily, then again to the target dose of 25 mg twice daily. A lower starting dose may be used (3.125 mg twice daily) and/or the rate of up-titration may be slowed if clinically indicated (e.g., due to low blood pressure or heart rate, or fluid retention). Patients should be maintained on lower doses if higher doses are not tolerated. The recommended dosing regimen need not be altered in patients who received treatment with an IV or oral β-blocker during the acute phase of the myocardial infarction.

Hypertension

DOSAGE MUST BE INDIVIDUALIZED. The recommended starting dose of COREG is 6.25 mg twice daily. If this dose is tolerated, using standing systolic pressure measured about 1 hour after dosing as a guide, the dose should be maintained for 7 to 14 days, and then increased to 12.5 mg twice daily if needed, based on trough blood pressure, again using standing systolic pressure 1 hour after dosing as a guide for tolerance. This dose should also be maintained for 7 to 14 days and can then be adjusted upward to 25 mg twice daily if tolerated and needed. The full antihypertensive effect of COREG is seen within 7 to 14 days. Total daily dose should not exceed 50 mg.

Concomitant administration with a diuretic can be expected to produce additive effects and exaggerate the orthostatic component of carvedilol action.

Hepatic Impairment

COREG should not be given to patients with severe hepatic impairment.

COREG is contraindicated in the following conditions:

• Bronchial asthma or related bronchospastic conditions. Deaths from status asthmaticus have been reported following single doses of COREG.
• Second-or third-degree AV block.
• Sick sinus syndrome.
• Severe bradycardia (unless a permanent pacemaker is in place).
• Patients with cardiogenic shock or who have decompensated heart failure requiring the use of intravenous inotropic therapy. Such patients should first be weaned from intravenous therapy before initiating COREG.
• Patients with severe hepatic impairment.
• Patients with a history of a serious hypersensitivity reaction (e.g., Stevens-Johnson syndrome, anaphylactic reaction, angioedema) to any component of this medication or other medications containing carvedilol.

WARNINGS

Included as part of the "PRECAUTIONS" Section

PRECAUTIONS

Cessation Of Therapy

Patients with coronary artery disease, who are being treated with COREG, should be advised against abrupt discontinuation of therapy. Severe exacerbation of angina and the occurrence of myocardial infarction and ventricular arrhythmias have been reported in patients with angina following the abrupt discontinuation of therapy with β-blockers. The last 2 complications may occur with or without preceding exacerbation of the angina pectoris. As with other β-blockers, when discontinuation of COREG is planned, the patients should be carefully observed and advised to limit physical activity to a minimum. COREG should be discontinued over 1 to 2 weeks whenever possible. If the angina worsens or acute coronary insufficiency develops, it is recommended that COREG be promptly reinstituted, at least temporarily. Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue therapy with COREG abruptly even in patients treated only for hypertension or heart failure.

Bradycardia

In clinical trials, COREG caused bradycardia in about 2% of hypertensive subjects, 9% of subjects with heart failure, and 6.5% of subjects with myocardial infarction and left ventricular dysfunction. If pulse rate drops below 55 beats per minute, the dosage should be reduced.

Hypotension

In clinical trials of primarily mild-to-moderate heart failure, hypotension and postural hypotension occurred in 9.7% and syncope in 3.4% of subjects receiving COREG compared with 3.6% and 2.5% of placebo subjects, respectively. The risk for these events was highest during the first 30 days of dosing, corresponding to the up-titration period and was a cause for discontinuation of therapy in 0.7% of subjects receiving COREG, compared with 0.4% of placebo subjects. In a long-term, placebo-controlled trial in severe heart failure (COPERNICUS), hypotension and postural hypotension occurred in 15.1% and syncope in 2.9% of heart failure subjects receiving COREG compared with 8.7% and 2.3% of placebo subjects, respectively. These events were a cause for discontinuation of therapy in 1.1% of subjects receiving COREG, compared with 0.8% of placebo subjects.

Postural hypotension occurred in 1.8% and syncope in 0.1% of hypertensive subjects, primarily following the initial dose or at the time of dose increase and was a cause for discontinuation of therapy in 1% of subjects.

In the CAPRICORN trial of survivors of an acute myocardial infarction, hypotension or postural hypotension occurred in 20.2% of subjects receiving COREG compared with 12.6% of placebo subjects. Syncope was reported in 3.9% and 1.9% of subjects, respectively. These events were a cause for discontinuation of therapy in 2.5% of subjects receiving COREG, compared with 0.2% of placebo subjects.

Starting with a low dose, administration with food, and gradual up-titration should decrease the likelihood of syncope or excessive hypotension. During initiation of therapy, the patient should be cautioned to avoid situations such as driving or hazardous tasks, where injury could result should syncope occur.

Heart Failure/Fluid Retention

Worsening heart failure or fluid retention may occur during up-titration of carvedilol. If such symptoms occur, diuretics should be increased and the carvedilol dose should not be advanced until clinical stability resumes. Occasionally it is necessary to lower the carvedilol dose or temporarily discontinue it. Such episodes do not preclude subsequent successful titration of, or a favorable response to, carvedilol. In a placebo-controlled trial of subjects with severe heart failure, worsening heart failure during the first 3 months was reported to a similar degree with carvedilol and with placebo. When treatment was maintained beyond 3 months, worsening heart failure was reported less frequently in subjects treated with carvedilol than with placebo. Worsening heart failure observed during long-term therapy is more likely to be related to the patients’ underlying disease than to treatment with carvedilol.

Non-Allergic Bronchospasm

Patients with bronchospastic disease (e.g., chronic bronchitis, emphysema) should, in general, not receive β-blockers. COREG may be used with caution, however, in patients who do not respond to, or cannot tolerate, other antihypertensive agents. It is prudent, if COREG is used, to use the smallest effective dose, so that inhibition of endogenous or exogenous β-agonists is minimized.

In clinical trials of subjects with heart failure, subjects with bronchospastic disease were enrolled if they did not require oral or inhaled medication to treat their bronchospastic disease. In such patients, it is recommended that carvedilol be used with caution. The dosing recommendations should be followed closely and the dose should be lowered if any evidence of bronchospasm is observed during up-titration.

Glycemic Control In Type 2 Diabetes

In general, β-blockers may mask some of the manifestations of hypoglycemia, particularly tachycardia. Nonselective β-blockers may potentiate insulin-induced hypoglycemia and delay recovery of serum glucose levels. Patients subject to spontaneous hypoglycemia or diabetic patients receiving insulin or oral hypoglycemic agents should be cautioned about these possibilities.

In patients with heart failure and diabetes, carvedilol therapy may lead to worsening hyperglycemia, which responds to intensification of hypoglycemic therapy. It is recommended that blood glucose be monitored when carvedilol dosing is initiated, adjusted, or discontinued. Trials designed to examine the effects of carvedilol on glycemic control in patients with diabetes and heart failure have not been conducted.

In a trial designed to examine the effects of carvedilol on glycemic control in a population with mild-to-moderate hypertension and well-controlled type 2 diabetes mellitus, carvedilol had no adverse effect on glycemic control, based on HbA1c measurements.

Peripheral Vascular Disease

β-blockers can precipitate or aggravate symptoms of arterial insufficiency in patients with peripheral vascular disease. Caution should be exercised in such individuals.

Deterioration Of Renal Function

Rarely, use of carvedilol in patients with heart failure has resulted in deterioration of renal function. Patients at risk appear to be those with low blood pressure (systolic blood pressure less than 100 mm Hg), ischemic heart disease and diffuse vascular disease, and/or underlying renal insufficiency. Renal function has returned to baseline when carvedilol was stopped. In patients with these risk factors it is recommended that renal function be monitored during up-titration of carvedilol and the drug discontinued or dosage reduced if worsening of renal function occurs.

Major Surgery

Chronically administered β-blocking therapy should not be routinely withdrawn prior to major surgery; however, the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures.

Thyrotoxicosis

β-adrenergic blockade may mask clinical signs of hyperthyroidism, such as tachycardia. Abrupt withdrawal of β-blockade may be followed by an exacerbation of the symptoms of hyperthyroidism or may precipitate thyroid storm.

Pheochromocytoma

In patients with pheochromocytoma, an α-blocking agent should be initiated prior to the use of any β-blocking agent. Although carvedilol has both α-and β-blocking pharmacologic activities, there has been no experience with its use in this condition. Therefore, caution should be taken in the administration of carvedilol to patients suspected of having pheochromocytoma.

Prinzmetal’s Variant Angina

Agents with non-selective β-blocking activity may provoke chest pain in patients with Prinzmetal’s variant angina. There has been no clinical experience with carvedilol in these patients although the α-blocking activity may prevent such symptoms. However, caution should be taken in the administration of carvedilol to patients suspected of having Prinzmetal’s variant angina.

Risk Of Anaphylactic Reaction

While taking β-blockers, patients with a history of severe anaphylactic reaction to a variety of allergens may be more reactive to repeated challenge, either accidental, diagnostic, or therapeutic. Such patients may be unresponsive to the usual doses of epinephrine used to treat allergic reaction.

Intraoperative Floppy Iris Syndrome

Intraoperative Floppy Iris Syndrome (IFIS) has been observed during cataract surgery in some patients treated with alpha-1 blockers (COREG is an alpha/beta blocker). This variant of small pupil syndrome is characterized by the combination of a flaccid iris that billows in response to intraoperative irrigation currents, progressive intraoperative miosis despite preoperative dilation with standard mydriatic drugs, and potential prolapse of the iris toward the phacoemulsification incisions. The patient’s ophthalmologist should be prepared for possible modifications to the surgical technique, such as utilization of iris hooks, iris dilator rings, or viscoelastic substances. There does not appear to be a benefit of stopping alpha-1 blocker therapy prior to cataract surgery.

Patient Counseling Information

Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).

Patients taking COREG should be advised of the following:

• Patients should take COREG with food.
• Patients should not interrupt or discontinue using COREG without a physician’s advice.
• Patients with heart failure should consult their physician if they experience signs or symptoms of worsening heart failure such as weight gain or increasing shortness of breath.
• Patients may experience a drop in blood pressure when standing, resulting in dizziness and, rarely, fainting. Patients should sit or lie down when these symptoms of lowered blood pressure occur.
• If experiencing dizziness or fatigue, patients should avoid driving or hazardous tasks.
• Patients should consult a physician if they experience dizziness or faintness, in case the dosage should be adjusted.
• Diabetic patients should report any changes in blood sugar levels to their physician.
• Contact lens wearers may experience decreased lacrimation.

COREG, COREG CR, and TILTAB are trademarks owned by or licensed to the GSK group of companies.

The other brand listed is a trademark owned by or licensed to its owner and is not owned by or licensed to the GSK group of companies. The maker of this brand is not affiliated with and does not endorse the GSK group of companies or its products.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment Of Fertility

In 2-year studies conducted in rats given carvedilol at doses up to 75 mg per kg per day (12 times the MRHD as mg per m²) or in mice given up to 200 mg per kg per day (16 times the MRHD as mg per m²), carvedilol had no carcinogenic effect.

Carvedilol was negative when tested in a battery of genotoxicity assays, including the Ames and the CHO/HGPRT assays for mutagenicity and the in vitro hamster micronucleus and in vivo human lymphocyte cell tests for clastogenicity.

In a combined fertility/developmental/post-natal toxicity study, rats were given carvedilol (12, 60, 300 mg per kg per day) orally by gavage for 2 weeks before mating and through mating, gestation, and weaning for females and for 62 days prior to and through mating for males. At a dosage of 300 mg per kg per day (greater than or equal to 50 times the MRHD as mg per m²) carvedilol was toxic to adult rats (sedation, reduced weight gain) and was associated with a reduced number of successful matings, prolonged mating time, fewer corpora lutea and implants per dam, fewer live pups per litter, and delays in physical growth/development. The no-effect level for overt toxicity and impairment of fertility was 60 mg per kg per day (10 times the MRHD as mg per m²).

Use In Specific Populations

Pregnancy

Risk Summary

Available data regarding use of COREG in pregnant women are insufficient to determine whether there are drug-associated risks of adverse developmental outcomes. There are risks to the mother and fetus associated with poorly controlled hypertension in pregnancy. The use of beta blockers during the third trimester of pregnancy may increase the risk of hypotension, bradycardia, hypoglycemia, and respiratory depression in the neonate [see Clinical Considerations]. In animal reproduction studies, there was no evidence of adverse developmental outcomes at clinically relevant doses [see Data]. Oral administration of carvedilol to pregnant rats during organogenesis resulted in post-implantation loss, decreased fetal body weight, and an increased frequency of delayed fetal skeletal development at maternally toxic doses that were 50 times the maximum recommended human dose (MRHD). In addition, oral administration of carvedilol to pregnant rabbits during organogenesis resulted in increased post-implantation loss at doses 25 times the MRHD [see Data].

The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Clinical Considerations

Disease-Associated Maternal and/or Embryo/Fetal Risk

Hypertension in pregnancy increases the maternal risk for pre-eclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section and post-partum hemorrhage). Hypertension increases the fetal risk for intrauterine growth restriction and intrauterine death. Pregnant women with hypertension should be carefully monitored and managed accordingly.

Fetal/Neonatal Adverse Reactions

Neonates of women with hypertension who are treated with beta-blockers during the third trimester of pregnancy may be at increased risk for hypotension, bradycardia, hypoglycemia, and respiratory depression. Observe newborns for symptoms of hypotension, bradycardia, hypoglycemia, and respiratory depression and manage accordingly.

Data

Animal Data

Studies performed in rats and rabbits given carvedilol during fetal organogenesis revealed increased post-implantation loss in rats at a maternally toxic dose of 300 mg per kg per day (50 times the MRHD as mg per m²) and in rabbits (in the absence of maternal toxicity) at doses of 75 mg per kg per day (25 times the MRHD as mg per m²). In the rats, there was also a decrease in fetal body weight at 300 mg per kg per day (50 times the MRHD as mg per m²) accompanied by an increased incidence of fetuses with delayed skeletal development. In rats, the no-effect level for embryo-fetal toxicity was 60 mg per kg per day (10 times the MRHD as mg per m²); in rabbits, it was 15 mg per kg per day (5 times the MRHD as mg per m²). In a pre-and post-natal development study in rats administered carvedilol from late gestation through lactation, increased embryo-lethality was observed at a maternally toxic dose of 200 mg per kg per day (approximately 32 times the MRHD as mg per m²), and pup mortality and delays in physical growth/development were observed at 60 mg per kg per day (10 times the MRHD as mg per m²) in the absence of maternal toxicity. The no-effect level was 12 mg per kg per day (2 times the MRHD as mg per m²). Carvedilol was present in fetal rat tissue.

Lactation

Risk Summary

There are no data on the presence of carvedilol in human milk, the effects on the breastfed infant, or the effects on milk production. Carvedilol is present in the milk of lactating rats. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for COREG and any potential adverse effects on the breastfed infant from COREG or from the underlying maternal condition.

Pediatric Use

Effectiveness of COREG in patients younger than 18 years has not been established.

In a double-blind trial, 161 children (mean age: 6 years; range: 2 months to 17 years; 45% younger than 2 years) with chronic heart failure [NYHA class II-IV, left ventricular ejection fraction less than 40% for children with a systemic left ventricle (LV), and moderate-severe ventricular dysfunction qualitatively by echo for those with a systemic ventricle that was not an LV] who were receiving standard background treatment were randomized to placebo or to 2 dose levels of carvedilol. These dose levels produced placebo-corrected heart rate reduction of 4 to 6 heart beats per minute, indicative of β-blockade activity. Exposure appeared to be lower in pediatric subjects than adults. After 8 months of follow-up, there was no significant effect of treatment on clinical outcomes. Adverse reactions in this trial that occurred in greater than 10% of subjects treated with COREG and at twice the rate of placebo-treated subjects included chest pain (17% versus 6%), dizziness (13% versus 2%), and dyspnea (11% versus 0%).

Geriatric Use

Of the 765 subjects with heart failure randomized to COREG in U.S. clinical trials, 31% (235) were aged 65 years or older, and 7.3% (56) were aged 75 years or older. Of the 1,156 subjects randomized to COREG in a long-term, placebo-controlled trial in severe heart failure, 47% (547) were aged 65 years or older, and 15% (174) were aged 75 years or older. Of 3,025 subjects receiving COREG in heart failure trials worldwide, 42% were aged 65 years or older.

Of the 975 subjects with myocardial infarction randomized to COREG in the CAPRICORN trial, 48% (468) were aged 65 years or older, and 11% (111) were aged 75 years or older.

Of the 2,065 hypertensive subjects in U.S. clinical trials of efficacy or safety who were treated with COREG, 21% (436) were aged 65 years or older. Of 3,722 subjects receiving COREG in hypertension clinical trials conducted worldwide, 24% were aged 65 years or older.

With the exception of dizziness in hypertensive subjects (incidence 8.8% in the elderly versus 6% in younger subjects), no overall differences in the safety or effectiveness (see Figures 2 and 4) were observed between the older subjects and younger subjects in each of these populations. Similarly, other reported clinical experience has not identified differences in responses between the elderly and younger subjects, but greater sensitivity of some older individuals cannot be ruled out.

SIDE EFFECTS

Clinical Studies 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 with rates in the clinical trials of another drug and may not reflect the rates observed in practice.

COREG has been evaluated for safety in subjects with heart failure (mild, moderate, and severe), in subjects with left ventricular dysfunction following myocardial infarction and in hypertensive subjects. The observed adverse event profile was consistent with the pharmacology of the drug and the health status of the subjects in the clinical trials. Adverse events reported for each of these patient populations are provided below. Excluded are adverse events considered too general to be informative, and those not reasonably associated with the use of the drug because they were associated with the condition being treated or are very common in the treated population. Rates of adverse events were generally similar across demographic subsets (men and women, elderly and non-elderly, blacks and non-blacks).

Heart Failure

COREG has been evaluated for safety in heart failure in more than 4,500 subjects worldwide of whom more than 2,100 participated in placebo-controlled clinical trials. Approximately 60% of the total treated population in placebo-controlled clinical trials received COREG for at least 6 months and 30% received COREG for at least 12 months. In the COMET trial, 1,511 subjects with mild-to-moderate heart failure were treated with COREG for up to 5.9 years (mean: 4.8 years). Both in U.S. clinical trials in mild-to-moderate heart failure that compared COREG in daily doses up to 100 mg (n = 765) with placebo (n = 437), and in a multinational clinical trial in severe heart failure (COPERNICUS) that compared COREG in daily doses up to 50 mg (n = 1,156) with placebo (n = 1,133), discontinuation rates for adverse experiences were similar in carvedilol and placebo subjects. In placebo-controlled clinical trials, the only cause of discontinuation greater than 1% and occurring more often on carvedilol was dizziness (1.3% on carvedilol, 0.6% on placebo in the COPERNICUS trial).

Table 1 shows adverse events reported in subjects with mild-to-moderate heart failure enrolled in U.S. placebo-controlled clinical trials, and with severe heart failure enrolled in the COPERNICUS trial. Shown are adverse events that occurred more frequently in drug-treated subjects than placebo-treated subjects with an incidence of greater than 3% in subjects treated with carvedilol regardless of causality. Median trial medication exposure was 6.3 months for both carvedilol and placebo subjects in the trials of mild-to-moderate heart failure and 10.4 months in the trial of subjects with severe heart failure. The adverse event profile of COREG observed in the long-term COMET trial was generally similar to that observed in the U.S. Heart Failure Trials.

Table 1. Adverse Events (%) Occurring More Frequently with COREG than with Placebo in Subjects with Mild-to-Moderate Heart Failure (HF) Enrolled in U.S. Heart Failure Trials or in Subjects with Severe Heart Failure in the COPERNICUS Trial (Incidence >3% in Subjects Treated with Carvedilol, Regardless of Causality)

Cardiac failure and dyspnea were also reported in these trials, but the rates were equal or greater in subjects who received placebo.

The following adverse events were reported with a frequency of greater than 1% but less than or equal to 3% and more frequently with COREG in either the U.S. placebo-controlled trials in subjects with mild-to-moderate heart failure or in subjects with severe heart failure in the COPERNICUS trial.

Incidence Greater Than 1% To Less Than Or Equal To 3%

Body as a Whole: Allergy, malaise, hypovolemia, fever, leg edema.

Cardiovascular: Fluid overload, postural hypotension, aggravated angina pectoris, AV block, palpitation, hypertension.

Central and Peripheral Nervous System: Hypesthesia, vertigo, paresthesia.

Gastrointestinal: Melena, periodontitis.

Liver and Biliary System: SGPT increased, SGOT increased.

Metabolic and Nutritional: Hyperuricemia, hypoglycemia, hyponatremia, increased alkaline phosphatase, glycosuria, hypervolemia, diabetes mellitus, GGT increased, weight loss, hyperkalemia, creatinine increased.

Musculoskeletal: Muscle cramps.

Platelet, Bleeding, and Clotting: Prothrombin decreased, purpura, thrombocytopenia.

Psychiatric: Somnolence.

Reproductive, male: Impotence.

Special Senses: Blurred vision.

Urinary System: Renal insufficiency, albuminuria, hematuria.

Left Ventricular Dysfunction Following Myocardial Infarction

COREG has been evaluated for safety in survivors of an acute myocardial infarction with left ventricular dysfunction in the CAPRICORN trial which involved 969 subjects who received COREG and 980 who received placebo. Approximately 75% of the subjects received COREG for at least 6 months and 53% received COREG for at least 12 months. Subjects were treated for an average of 12.9 months and 12.8 months with COREG and placebo, respectively.

The most common adverse events reported with COREG in the CAPRICORN trial were consistent with the profile of the drug in the U.S. heart failure trials and the COPERNICUS trial. The only additional adverse events reported in CAPRICORN in greater than 3% of the subjects and more commonly on carvedilol were dyspnea, anemia, and lung edema. The following adverse events were reported with a frequency of greater than 1% but less than or equal to 3% and more frequently with COREG: flu syndrome, cerebrovascular accident, peripheral vascular disorder, hypotonia, depression, gastrointestinal pain, arthritis, and gout. The overall rates of discontinuations due to adverse events were similar in both groups of subjects. In this database, the only cause of discontinuation greater than 1% and occurring more often on carvedilol was hypotension (1.5% on carvedilol, 0.2% on placebo).

Hypertension

COREG has been evaluated for safety in hypertension in more than 2,193 subjects in U.S. clinical trials and in 2,976 subjects in international clinical trials. Approximately 36% of the total treated population received COREG for at least 6 months. Most adverse events reported during therapy with COREG were of mild to moderate severity. In U.S. controlled clinical trials directly comparing COREG in doses up to 50 mg (n = 1,142) with placebo (n = 462), 4.9% of subjects receiving COREG discontinued for adverse events versus 5.2% of placebo subjects. Although there was no overall difference in discontinuation rates, discontinuations were more common in the carvedilol group for postural hypotension (1% versus 0). The overall incidence of adverse events in U.S. placebo-controlled trials increased with increasing dose of COREG. For individual adverse events this could only be distinguished for dizziness, which increased in frequency from 2% to 5% as total daily dose increased from 6.25 mg to 50 mg.

Table 2 shows adverse events in U.S. placebo-controlled clinical trials for hypertension that occurred with an incidence of greater than or equal to 1% regardless of causality and that were more frequent in drug-treated subjects than placebo-treated subjects.

Table 2. Adverse Events (%) Occurring in U.S. Placebo-Controlled Hypertension Trials (Incidence ≥1%, Regardless of Causality)^a

Dyspnea and fatigue were also reported in these trials, but the rates were equal or greater in subjects who received placebo.

The following adverse events not described above were reported as possibly or probably related to COREG in worldwide open or controlled trials with COREG in subjects with hypertension or heart failure.

Incidence Greater Than 0.1% To Less Than Or Equal To 1%

Cardiovascular: Peripheral ischemia, tachycardia.

Central and Peripheral Nervous System: Hypokinesia.

Gastrointestinal: Bilirubinemia, increased hepatic enzymes (0.2% of hypertension patients and 0.4% of heart failure patients were discontinued from therapy because of increases in hepatic enzymes).

Psychiatric: Nervousness, sleep disorder, aggravated depression, impaired concentration, abnormal thinking, paroniria, emotional lability.

Respiratory System: Asthma.

Reproductive, male: Decreased libido.

Skin and Appendages: Pruritus, rash erythematous, rash maculopapular, rash psoriaform, photosensitivity reaction.

Special Senses: Tinnitus.

Urinary System: Micturition frequency increased.

Autonomic Nervous System: Dry mouth, sweating increased.

Metabolic and Nutritional: Hypokalemia, hypertriglyceridemia.

Hematologic: Anemia, leukopenia.

The following events were reported in less than or equal to 0.1% of subjects and are potentially important: complete AV block, bundle branch block, myocardial ischemia, cerebrovascular disorder, convulsions, migraine, neuralgia, paresis, anaphylactoid reaction, alopecia, exfoliative dermatitis, amnesia, GI hemorrhage, bronchospasm, pulmonary edema, decreased hearing, respiratory alkalosis, increased BUN, decreased HDL, pancytopenia, and atypical lymphocytes.

Laboratory Abnormalities

Reversible elevations in serum transaminases (ALT or AST) have been observed during treatment with COREG. Rates of transaminase elevations (2 to 3 times the upper limit of normal) observed during controlled clinical trials have generally been similar between subjects treated with COREG and those treated with placebo. However, transaminase elevations, confirmed by rechallenge, have been observed with COREG. In a long-term, placebo-controlled trial in severe heart failure, subjects treated with COREG had lower values for hepatic transaminases than subjects treated with placebo, possibly because improvements in cardiac function induced by COREG led to less hepatic congestion and/or improved hepatic blood flow.

COREG has not been associated with clinically significant changes in serum potassium, total triglycerides, total cholesterol, HDL cholesterol, uric acid, blood urea nitrogen, or creatinine. No clinically relevant changes were noted in fasting serum glucose in hypertensive patients; fasting serum glucose was not evaluated in the heart failure clinical trials.

Postmarketing Experience

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

Blood And Lymphatic System Disorders

Aplastic anemia.

Immune System Disorders

Hypersensitivity (e.g., anaphylactic reactions, angioedema, urticaria).

Renal And Urinary Disorders

Urinary incontinence.

Respiratory, Thoracic, And Mediastinal Disorders

Interstitial pneumonitis.

Skin And Subcutaneous Tissue Disorders

Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme.

DRUG INTERACTIONS

CYP2D6 Inhibitors And Poor Metabolizers

Interactions of carvedilol with potent inhibitors of CYP2D6 isoenzyme (such as quinidine, fluoxetine, paroxetine, and propafenone) have not been studied, but these drugs would be expected to increase blood levels of the R(+) enantiomer of carvedilol. Retrospective analysis of side effects in clinical trials showed that poor 2D6 metabolizers had a higher rate of dizziness during up-titration, presumably resulting from vasodilating effects of the higher concentrations of the α-blocking R(+) enantiomer.

Hypotensive Agents

Patients taking a β-blocker and a drug that can deplete catecholamines (e.g., reserpine and monoamine oxidase inhibitors) should be observed closely for signs of hypotension and/or severe bradycardia.

Concomitant administration of clonidine with a β-blocker may cause hypotension and bradycardia. When concomitant treatment with a β-blocker and clonidine is to be terminated, the β-blocker should be discontinued first. Clonidine therapy can then be discontinued several days later by gradually decreasing the dosage.

Cyclosporine

Modest increases in mean trough cyclosporine concentrations were observed following initiation of carvedilol treatment in 21 renal transplant subjects suffering from chronic vascular rejection. In about 30% of subjects, the dose of cyclosporine had to be reduced in order to maintain cyclosporine concentrations within the therapeutic range, while in the remainder no adjustment was needed. On the average for the group, the dose of cyclosporine was reduced about 20% in these subjects. Due to wide interindividual variability in the dose adjustment required, it is recommended that cyclosporine concentrations be monitored closely after initiation of carvedilol therapy and that the dose of cyclosporine be adjusted as appropriate.

Digitalis Glycosides

Both digitalis glycosides and β-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia. Digoxin concentrations are increased by about 15% when digoxin and carvedilol are administered concomitantly. Therefore, increased monitoring of digoxin is recommended when initiating, adjusting, or discontinuing COREG.

Inducers/Inhibitors Of Hepatic Metabolism

Rifampin reduced plasma concentrations of carvedilol by about 70%. Cimetidine increased AUC by about 30% but caused no change in Cmax.

Amiodarone

Amiodarone and its metabolite desethyl amiodarone, inhibitors of CYP2C9, and P-glycoprotein increased concentrations of the S(-)-enantiomer of carvedilol by at least 2 fold. The concomitant administration of amiodarone or other CYP2C9 inhibitors such as fluconazole with COREG may enhance the β-blocking activity, resulting in further slowing of the heart rate or cardiac conduction. Patients should be observed for signs of bradycardia or heart block, particularly when one agent is added to pre-existing treatment with the other.

Calcium Channel Blockers

Conduction disturbance (rarely with hemodynamic compromise) has been observed when COREG is coadministered with diltiazem. As with other β-blockers, if COREG is administered with calcium channel blockers of the verapamil or diltiazem type, it is recommended that ECG and blood pressure be monitored.

Insulin Or Oral Hypoglycemics

β-blockers may enhance the blood-sugar-reducing effect of insulin and oral hypoglycemics. Therefore, in patients taking insulin or oral hypoglycemics, regular monitoring of blood glucose is recommended.

Anesthesia

If treatment with COREG is to be continued perioperatively, particular care should be taken when anesthetic agents that depress myocardial function, such as ether, cyclopropane, and trichloroethylene, are used.

Risk Summary

Available data regarding use of COREG in pregnant women are insufficient to determine whether there are drug-associated risks of adverse developmental outcomes. There are risks to the mother and fetus associated with poorly controlled hypertension in pregnancy. The use of beta blockers during the third trimester of pregnancy may increase the risk of hypotension, bradycardia, hypoglycemia, and respiratory depression in the neonate [see Clinical Considerations]. In animal reproduction studies, there was no evidence of adverse developmental outcomes at clinically relevant doses [see Data]. Oral administration of carvedilol to pregnant rats during organogenesis resulted in post-implantation loss, decreased fetal body weight, and an increased frequency of delayed fetal skeletal development at maternally toxic doses that were 50 times the maximum recommended human dose (MRHD). In addition, oral administration of carvedilol to pregnant rabbits during organogenesis resulted in increased post-implantation loss at doses 25 times the MRHD [see Data].

The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Clinical Considerations

Disease-Associated Maternal and/or Embryo/Fetal Risk

Hypertension in pregnancy increases the maternal risk for pre-eclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section and post-partum hemorrhage). Hypertension increases the fetal risk for intrauterine growth restriction and intrauterine death. Pregnant women with hypertension should be carefully monitored and managed accordingly.

Fetal/Neonatal Adverse Reactions

Neonates of women with hypertension who are treated with beta-blockers during the third trimester of pregnancy may be at increased risk for hypotension, bradycardia, hypoglycemia, and respiratory depression. Observe newborns for symptoms of hypotension, bradycardia, hypoglycemia, and respiratory depression and manage accordingly.

Data

Animal Data

Studies performed in rats and rabbits given carvedilol during fetal organogenesis revealed increased post-implantation loss in rats at a maternally toxic dose of 300 mg per kg per day (50 times the MRHD as mg per m²) and in rabbits (in the absence of maternal toxicity) at doses of 75 mg per kg per day (25 times the MRHD as mg per m²). In the rats, there was also a decrease in fetal body weight at 300 mg per kg per day (50 times the MRHD as mg per m²) accompanied by an increased incidence of fetuses with delayed skeletal development. In rats, the no-effect level for embryo-fetal toxicity was 60 mg per kg per day (10 times the MRHD as mg per m²); in rabbits, it was 15 mg per kg per day (5 times the MRHD as mg per m²). In a pre-and post-natal development study in rats administered carvedilol from late gestation through lactation, increased embryo-lethality was observed at a maternally toxic dose of 200 mg per kg per day (approximately 32 times the MRHD as mg per m²), and pup mortality and delays in physical growth/development were observed at 60 mg per kg per day (10 times the MRHD as mg per m²) in the absence of maternal toxicity. The no-effect level was 12 mg per kg per day (2 times the MRHD as mg per m²). Carvedilol was present in fetal rat tissue.

Clinical Studies 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 with rates in the clinical trials of another drug and may not reflect the rates observed in practice.

COREG has been evaluated for safety in subjects with heart failure (mild, moderate, and severe), in subjects with left ventricular dysfunction following myocardial infarction and in hypertensive subjects. The observed adverse event profile was consistent with the pharmacology of the drug and the health status of the subjects in the clinical trials. Adverse events reported for each of these patient populations are provided below. Excluded are adverse events considered too general to be informative, and those not reasonably associated with the use of the drug because they were associated with the condition being treated or are very common in the treated population. Rates of adverse events were generally similar across demographic subsets (men and women, elderly and non-elderly, blacks and non-blacks).

Heart Failure

COREG has been evaluated for safety in heart failure in more than 4,500 subjects worldwide of whom more than 2,100 participated in placebo-controlled clinical trials. Approximately 60% of the total treated population in placebo-controlled clinical trials received COREG for at least 6 months and 30% received COREG for at least 12 months. In the COMET trial, 1,511 subjects with mild-to-moderate heart failure were treated with COREG for up to 5.9 years (mean: 4.8 years). Both in U.S. clinical trials in mild-to-moderate heart failure that compared COREG in daily doses up to 100 mg (n = 765) with placebo (n = 437), and in a multinational clinical trial in severe heart failure (COPERNICUS) that compared COREG in daily doses up to 50 mg (n = 1,156) with placebo (n = 1,133), discontinuation rates for adverse experiences were similar in carvedilol and placebo subjects. In placebo-controlled clinical trials, the only cause of discontinuation greater than 1% and occurring more often on carvedilol was dizziness (1.3% on carvedilol, 0.6% on placebo in the COPERNICUS trial).

Table 1 shows adverse events reported in subjects with mild-to-moderate heart failure enrolled in U.S. placebo-controlled clinical trials, and with severe heart failure enrolled in the COPERNICUS trial. Shown are adverse events that occurred more frequently in drug-treated subjects than placebo-treated subjects with an incidence of greater than 3% in subjects treated with carvedilol regardless of causality. Median trial medication exposure was 6.3 months for both carvedilol and placebo subjects in the trials of mild-to-moderate heart failure and 10.4 months in the trial of subjects with severe heart failure. The adverse event profile of COREG observed in the long-term COMET trial was generally similar to that observed in the U.S. Heart Failure Trials.

Table 1. Adverse Events (%) Occurring More Frequently with COREG than with Placebo in Subjects with Mild-to-Moderate Heart Failure (HF) Enrolled in U.S. Heart Failure Trials or in Subjects with Severe Heart Failure in the COPERNICUS Trial (Incidence >3% in Subjects Treated with Carvedilol, Regardless of Causality)

Cardiac failure and dyspnea were also reported in these trials, but the rates were equal or greater in subjects who received placebo.

The following adverse events were reported with a frequency of greater than 1% but less than or equal to 3% and more frequently with COREG in either the U.S. placebo-controlled trials in subjects with mild-to-moderate heart failure or in subjects with severe heart failure in the COPERNICUS trial.

Incidence Greater Than 1% To Less Than Or Equal To 3%

Body as a Whole: Allergy, malaise, hypovolemia, fever, leg edema.

Cardiovascular: Fluid overload, postural hypotension, aggravated angina pectoris, AV block, palpitation, hypertension.

Central and Peripheral Nervous System: Hypesthesia, vertigo, paresthesia.

Gastrointestinal: Melena, periodontitis.

Liver and Biliary System: SGPT increased, SGOT increased.

Metabolic and Nutritional: Hyperuricemia, hypoglycemia, hyponatremia, increased alkaline phosphatase, glycosuria, hypervolemia, diabetes mellitus, GGT increased, weight loss, hyperkalemia, creatinine increased.

Musculoskeletal: Muscle cramps.

Platelet, Bleeding, and Clotting: Prothrombin decreased, purpura, thrombocytopenia.

Psychiatric: Somnolence.

Reproductive, male: Impotence.

Special Senses: Blurred vision.

Urinary System: Renal insufficiency, albuminuria, hematuria.

Left Ventricular Dysfunction Following Myocardial Infarction

COREG has been evaluated for safety in survivors of an acute myocardial infarction with left ventricular dysfunction in the CAPRICORN trial which involved 969 subjects who received COREG and 980 who received placebo. Approximately 75% of the subjects received COREG for at least 6 months and 53% received COREG for at least 12 months. Subjects were treated for an average of 12.9 months and 12.8 months with COREG and placebo, respectively.

The most common adverse events reported with COREG in the CAPRICORN trial were consistent with the profile of the drug in the U.S. heart failure trials and the COPERNICUS trial. The only additional adverse events reported in CAPRICORN in greater than 3% of the subjects and more commonly on carvedilol were dyspnea, anemia, and lung edema. The following adverse events were reported with a frequency of greater than 1% but less than or equal to 3% and more frequently with COREG: flu syndrome, cerebrovascular accident, peripheral vascular disorder, hypotonia, depression, gastrointestinal pain, arthritis, and gout. The overall rates of discontinuations due to adverse events were similar in both groups of subjects. In this database, the only cause of discontinuation greater than 1% and occurring more often on carvedilol was hypotension (1.5% on carvedilol, 0.2% on placebo).

Hypertension

COREG has been evaluated for safety in hypertension in more than 2,193 subjects in U.S. clinical trials and in 2,976 subjects in international clinical trials. Approximately 36% of the total treated population received COREG for at least 6 months. Most adverse events reported during therapy with COREG were of mild to moderate severity. In U.S. controlled clinical trials directly comparing COREG in doses up to 50 mg (n = 1,142) with placebo (n = 462), 4.9% of subjects receiving COREG discontinued for adverse events versus 5.2% of placebo subjects. Although there was no overall difference in discontinuation rates, discontinuations were more common in the carvedilol group for postural hypotension (1% versus 0). The overall incidence of adverse events in U.S. placebo-controlled trials increased with increasing dose of COREG. For individual adverse events this could only be distinguished for dizziness, which increased in frequency from 2% to 5% as total daily dose increased from 6.25 mg to 50 mg.

Table 2 shows adverse events in U.S. placebo-controlled clinical trials for hypertension that occurred with an incidence of greater than or equal to 1% regardless of causality and that were more frequent in drug-treated subjects than placebo-treated subjects.

Table 2. Adverse Events (%) Occurring in U.S. Placebo-Controlled Hypertension Trials (Incidence ≥1%, Regardless of Causality)^a

Dyspnea and fatigue were also reported in these trials, but the rates were equal or greater in subjects who received placebo.

The following adverse events not described above were reported as possibly or probably related to COREG in worldwide open or controlled trials with COREG in subjects with hypertension or heart failure.

Incidence Greater Than 0.1% To Less Than Or Equal To 1%

Cardiovascular: Peripheral ischemia, tachycardia.

Central and Peripheral Nervous System: Hypokinesia.

Gastrointestinal: Bilirubinemia, increased hepatic enzymes (0.2% of hypertension patients and 0.4% of heart failure patients were discontinued from therapy because of increases in hepatic enzymes).

Psychiatric: Nervousness, sleep disorder, aggravated depression, impaired concentration, abnormal thinking, paroniria, emotional lability.

Respiratory System: Asthma.

Reproductive, male: Decreased libido.

Skin and Appendages: Pruritus, rash erythematous, rash maculopapular, rash psoriaform, photosensitivity reaction.

Special Senses: Tinnitus.

Urinary System: Micturition frequency increased.

Autonomic Nervous System: Dry mouth, sweating increased.

Metabolic and Nutritional: Hypokalemia, hypertriglyceridemia.

Hematologic: Anemia, leukopenia.

The following events were reported in less than or equal to 0.1% of subjects and are potentially important: complete AV block, bundle branch block, myocardial ischemia, cerebrovascular disorder, convulsions, migraine, neuralgia, paresis, anaphylactoid reaction, alopecia, exfoliative dermatitis, amnesia, GI hemorrhage, bronchospasm, pulmonary edema, decreased hearing, respiratory alkalosis, increased BUN, decreased HDL, pancytopenia, and atypical lymphocytes.

Laboratory Abnormalities

Reversible elevations in serum transaminases (ALT or AST) have been observed during treatment with COREG. Rates of transaminase elevations (2 to 3 times the upper limit of normal) observed during controlled clinical trials have generally been similar between subjects treated with COREG and those treated with placebo. However, transaminase elevations, confirmed by rechallenge, have been observed with COREG. In a long-term, placebo-controlled trial in severe heart failure, subjects treated with COREG had lower values for hepatic transaminases than subjects treated with placebo, possibly because improvements in cardiac function induced by COREG led to less hepatic congestion and/or improved hepatic blood flow.

COREG has not been associated with clinically significant changes in serum potassium, total triglycerides, total cholesterol, HDL cholesterol, uric acid, blood urea nitrogen, or creatinine. No clinically relevant changes were noted in fasting serum glucose in hypertensive patients; fasting serum glucose was not evaluated in the heart failure clinical trials.

Postmarketing Experience

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

Blood And Lymphatic System Disorders

Aplastic anemia.

Immune System Disorders

Hypersensitivity (e.g., anaphylactic reactions, angioedema, urticaria).

Renal And Urinary Disorders

Urinary incontinence.

Respiratory, Thoracic, And Mediastinal Disorders

Interstitial pneumonitis.

Skin And Subcutaneous Tissue Disorders

Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme.

Overdosage may cause severe hypotension, bradycardia, cardiac insufficiency, cardiogenic shock, and cardiac arrest. Respiratory problems, bronchospasms, vomiting, lapses of consciousness, and generalized seizures may also occur.

The patient should be placed in a supine position and, where necessary, kept under observation and treated under intensive-care conditions. The following agents may be administered:

For excessive bradycardia: Atropine, 2 mg IV.

To support cardiovascular function: Glucagon, 5 to 10 mg IV rapidly over 30 seconds, followed by a continuous infusion of 5 mg per hour; sympathomimetics (dobutamine, isoprenaline, adrenaline) at doses according to body weight and effect.

If peripheral vasodilation dominates, it may be necessary to administer adrenaline or noradrenaline with continuous monitoring of circulatory conditions. For therapy-resistant bradycardia, pacemaker therapy should be performed. For bronchospasm, β-sympathomimetics (as aerosol or IV) or aminophylline IV should be given. In the event of seizures, slow IV injection of diazepam or clonazepam is recommended.

NOTE: In the event of severe intoxication where there are symptoms of shock, treatment with antidotes must be continued for a sufficiently long period of time consistent with the 7-to 10-hour half-life of carvedilol.

Cases of overdosage with COREG alone or in combination with other drugs have been reported. Quantities ingested in some cases exceeded 1,000 milligrams. Symptoms experienced included low blood pressure and heart rate. Standard supportive treatment was provided and individuals recovered.

Heart Failure

The basis for the beneficial effects of COREG in heart failure is not established.

Two placebo-controlled trials compared the acute hemodynamic effects of COREG with baseline measurements in 59 and 49 subjects with NYHA class II-IV heart failure receiving diuretics, ACE inhibitors, and digitalis. There were significant reductions in systemic blood pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, and heart rate. Initial effects on cardiac output, stroke volume index, and systemic vascular resistance were small and variable.

These trials measured hemodynamic effects again at 12 to 14 weeks. COREG significantly reduced systemic blood pressure, pulmonary artery pressure, right atrial pressure, systemic vascular resistance, and heart rate, while stroke volume index was increased.

Among 839 subjects with NYHA class II-III heart failure treated for 26 to 52 weeks in 4 U.S. placebo-controlled trials, average left ventricular ejection fraction (EF) measured by radionuclide ventriculography increased by 9 EF units (%) in subjects receiving COREG and by 2 EF units in placebo subjects at a target dose of 25 to 50 mg twice daily. The effects of carvedilol on ejection fraction were related to dose. Doses of 6.25 mg twice daily, 12.5 mg twice daily, and 25 mg twice daily were associated with placebo-corrected increases in EF of 5 EF units, 6 EF units, and 8 EF units, respectively; each of these effects were nominally statistically significant.

Left Ventricular Dysfunction Following Myocardial Infarction

The basis for the beneficial effects of COREG in patients with left ventricular dysfunction following an acute myocardial infarction is not established.

Hypertension

The mechanism by which β-blockade produces an antihypertensive effect has not been established.

β-adrenoreceptor blocking activity has been demonstrated in animal and human studies showing that carvedilol (1) reduces cardiac output in normal subjects, (2) reduces exercise-and/or isoproterenol-induced tachycardia, and (3) reduces reflex orthostatic tachycardia. Significant β-adrenoreceptor blocking effect is usually seen within 1 hour of drug administration.

α₁-adrenoreceptor blocking activity has been demonstrated in human and animal studies, showing that carvedilol (1) attenuates the pressor effects of phenylephrine, (2) causes vasodilation, and (3) reduces peripheral vascular resistance. These effects contribute to the reduction of blood pressure and usually are seen within 30 minutes of drug administration.

Due to the α₁-receptor blocking activity of carvedilol, blood pressure is lowered more in the standing than in the supine position, and symptoms of postural hypotension (1.8%), including rare instances of syncope, can occur. Following oral administration, when postural hypotension has occurred, it has been transient and is uncommon when COREG is administered with food at the recommended starting dose and titration increments are closely followed.

In hypertensive patients with normal renal function, therapeutic doses of COREG decreased renal vascular resistance with no change in glomerular filtration rate or renal plasma flow. Changes in excretion of sodium, potassium, uric acid, and phosphorus in hypertensive patients with normal renal function were similar after COREG and placebo.

COREG has little effect on plasma catecholamines, plasma aldosterone, or electrolyte levels, but it does significantly reduce plasma renin activity when given for at least 4 weeks. It also increases levels of atrial natriuretic peptide.

COREG is rapidly and extensively absorbed following oral administration, with absolute bioavailability of approximately 25% to 35% due to a significant degree of first-pass metabolism. Following oral administration, the apparent mean terminal elimination half-life of carvedilol generally ranges from 7 to 10 hours. Plasma concentrations achieved are proportional to the oral dose administered. When administered with food, the rate of absorption is slowed, as evidenced by a delay in the time to reach peak plasma levels, with no significant difference in extent of bioavailability. Taking COREG with food should minimize the risk of orthostatic hypotension.

Carvedilol is extensively metabolized. Following oral administration of radiolabelled carvedilol to healthy volunteers, carvedilol accounted for only about 7% of the total radioactivity in plasma as measured by area under the curve (AUC). Less than 2% of the dose was excreted unchanged in the urine. Carvedilol is metabolized primarily by aromatic ring oxidation and glucuronidation.

The oxidative metabolites are further metabolized by conjugation via glucuronidation and sulfation. The metabolites of carvedilol are excreted primarily via the bile into the feces. Demethylation and hydroxylation at the phenol ring produce 3 active metabolites with β-receptor blocking activity. Based on preclinical studies, the 4’-hydroxyphenyl metabolite is approximately 13 times more potent than carvedilol for β-blockade.

Compared with carvedilol, the 3 active metabolites exhibit weak vasodilating activity. Plasma concentrations of the active metabolites are about one-tenth of those observed for carvedilol and have pharmacokinetics similar to the parent.

Carvedilol undergoes stereoselective first-pass metabolism with plasma levels of R(+)-carvedilol approximately 2 to 3 times higher than S(-)-carvedilol following oral administration in healthy subjects. The mean apparent terminal elimination half-lives for R(+)-carvedilol range from 5 to 9 hours compared with 7 to 11 hours for the S(-)-enantiomer.

The primary P450 enzymes responsible for the metabolism of both R(+) and S(-)-carvedilol in human liver microsomes were CYP2D6 and CYP2C9 and to a lesser extent CYP3A4, 2C19, 1A2, and 2E1. CYP2D6 is thought to be the major enzyme in the 4'-and 5'-hydroxylation of carvedilol, with a potential contribution from 3A4. CYP2C9 is thought to be of primary importance in the O-methylation pathway of S(-)-carvedilol.

Carvedilol is subject to the effects of genetic polymorphism with poor metabolizers of debrisoquin (a marker for cytochrome P450 2D6) exhibiting 2-to 3-fold higher plasma concentrations of R(+)-carvedilol compared with extensive metabolizers. In contrast, plasma levels of S(-)-carvedilol are increased only about 20% to 25% in poor metabolizers, indicating this enantiomer is metabolized to a lesser extent by cytochrome P450 2D6 than R(+)-carvedilol. The pharmacokinetics of carvedilol do not appear to be different in poor metabolizers of S-mephenytoin (patients deficient in cytochrome P450 2C19).

Carvedilol is more than 98% bound to plasma proteins, primarily with albumin. The plasma-protein binding is independent of concentration over the therapeutic range. Carvedilol is a basic, lipophilic compound with a steady-state volume of distribution of approximately 115 L, indicating substantial distribution into extravascular tissues. Plasma clearance ranges from 500 to 700 mL/min.