Carvedilol

Description

11 DESCRIPTION Carvedilol is a nonselective β-adrenergic blocking agent with α 1 -blocking activity. It is (±)-1-(Carbazol-4-yloxy)-3-[[2-(o-methoxyphenoxy)ethyl]amino]-2-propanol. Carvedilol is a racemic mixture with the following structure: Carvedilol, USP is a white to almost white crystalline powder with a molecular weight of 406.5 and a molecular formula of C 24 H 26 N 2 O 4 . It is freely soluble in dimethylsulfoxide; soluble in methylene chloride and methanol; sparingly soluble in 95% ethanol and isopropanol; slightly soluble in ethyl ether; and practically insoluble in water, gastric fluid (simulated, TS, pH 1.1), and intestinal fluid (simulated, TS without pancreatin, pH 7.5). Each carvedilol tablet, USP intended for oral administration contains 3.125 mg or 6.25 mg or 12.5 mg or 25 mg of carvedilol. In addition, each tablet contains the following inactive ingredients: colloidal silicon dioxide, crospovidone, hypromellose, lactose monohydrate, magnesium stearate, polyethylene glycol, povidone, talc and titanium dioxide. The product meets USP Dissolution Test 3. structured formula for carvedilol

What Is Carvedilol Used For?

1 INDICATIONS AND USAGE Carvedilol tablets are an alpha/beta-adrenergic blocking agent indicated for the treatment of: mild to severe chronic heart failure ( 1.1 ) left ventricular dysfunction following myocardial infarction in clinically stable patients( 1.2 ) hypertension( 1.3 ) 1.1 Heart Failure Carvedilol tablets are 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 [see Drug Interactions ( 7.4 ), Clinical Studies ( 14.1 )] . 1.2 Left Ventricular Dysfunction following Myocardial Infarction Carvedilol tablets are 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) [see Clinical Studies ( 14.2 )] . 1.3 Hypertension Carvedilol tablets are indicated for the management of essential hypertension [see Clinical Studies ( 14.3 , 14.4 )] . It can be used alone or in combination with other antihypertensive agents, especially thiazide-type diuretics [see Drug Interactions ( 7.2 )] .

Dosage and Administration

2 DOSAGE AND ADMINISTRATION Take with food. Individualize dosage and monitor during up-titration. ( 2 ) Heart failure: Start at 3.125 mg twice daily and increase to 6.25, 12.5, and then 25 mg twice daily over intervals of at least 2 weeks. Maintain lower doses if higher doses are not tolerated. ( 2.1 ) Left ventricular dysfunction following myocardial infarction: Start at 6.25 mg twice daily and increase to 12.5 mg then 25 mg twice daily after intervals of 3 to 10 days. A lower starting dose or slower titration may be used.( 2.2 ) Hypertension: Start at 6.25 mg twice daily and increase if needed for blood pressure control to 12.5 mg and then 25 mg twice daily over intervals of 1 to 2 weeks.( 2.3 ) Carvedilol should be taken with food to slow the rate of absorption and reduce the incidence of orthostatic effects. 2.1 Heart Failure DOSAGE MUST BE INDIVIDUALIZED AND CLOSELY MONITORED BY A PHYSICIAN DURING UP-TITRATION. Prior to initiation of Carvedilol tablets, it is recommended that fluid retention be minimized. The recommended starting dose of Carvedilol tablets are 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 Carvedilol tablets from that of the ACE inhibitor or to reduce temporarily the dose of the ACE inhibitor. The dose of Carvedilol tablets 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 Carvedilol tablets should be reduced if patients experience bradycardia (heart rate less than 55 beats per minute). Episodes of dizziness or fluid retention during initiation of Carvedilol tablets can generally be managed without discontinuation of treatment and do not preclude subsequent successful titration of, or a favorable response to, carvedilol. 2.2 Left Ventricular Dysfunction following Myocardial Infarction DOSAGE MUST BE INDIVIDUALIZED AND MONITORED DURING UP-TITRATION. Treatment with carvedilol tablets 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...

Side Effects (Adverse Reactions)

6 ADVERSE REACTIONS Most common adverse events ( 6.1 ): Heart failure and left ventricular dysfunction following myocardial infarction (≥10%): Dizziness, fatigue, hypotension, diarrhea, hyperglycemia, asthenia, bradycardia, weight increase. Hypertension (≥5%): Dizziness. To report SUSPECTED ADVERSE REACTIONS, contact Zydus Pharmaceuticals (USA) Inc. at 1- 877-993-8779 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 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. Carvedilol tablets have 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 Carvedilol tablets have 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 Carvedilol tablets for at least 6 months and 30% received Carvedilol tablets for at least 12 months. In the COMET trial, 1,511 subjects with mild-to-moderate heart failure were treated with Carvedilol tablets for up to 5.9 years (mean: 4.8 years). Both in US clinical trials in mild-to-moderate heart failure that compared Carvedilol tablets 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 Carvedilol tablets 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 US 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 Carvedilol tablets observed in the long-term COMET trial was generally similar to that observed in the US Heart Failure Trials. Table 1 Adverse Events (%) Occurring More Frequently with Carvedilol tablets than with Placebo in Subjects with Mild-to-Moderate Heart Failure (HF) Enrolled in US Heart Failure Trials or in Subjects with Severe Heart Failure in the COPERNICUS Trial (Incidence >3% in Subjects Treated with Carvedilol, Regardless of Causality) Mild-to-Moderate HF Severe HF Body System/ Adverse Event Carvedilol (n = 765) Placebo (n = 437) Carvedilol (n = 1,156) Placebo (n = 1,133) Body as a Whole Asthenia Fatigue Digoxin level...

Drug Interactions

7 DRUG INTERACTIONS CYP P450 2D6 enzyme inhibitors may increase and rifampin may decrease carvedilol levels. ( 7.1 , 7.5 ) Hypotensive agents (e.g., reserpine, MAO inhibitors, clonidine) may increase the risk of hypotension and/or severe bradycardia. ( 7.4 ) Cyclosporine or digoxin levels may increase. ( 7.3 , 7.4 ) Both digitalis glycosides and β-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia. ( 7.4 ) Amiodarone may increase carvedilol levels resulting in further slowing of the heart rate or cardiac conduction. ( 7.6 ) Verapamil- or diltiazem-type calcium channel blockers may affect ECG and/or blood pressure. ( 7.7 ) Insulin and oral hypoglycemics action may be enhanced. ( 7.8 ) 7.1 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 [see Clinical Pharmacology ( 12.3 )] . 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. 7.2 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. 7.3 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. 7.4 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...

Contraindications

4 CONTRAINDICATIONS Bronchial asthma or related bronchospastic conditions. ( 4 ) Second- or third-degree AV block. ( 4 ) Sick sinus syndrome. ( 4 ) Severe bradycardia (unless permanent pacemaker in place). ( 4 ) Patients in cardiogenic shock or decompensated heart failure requiring the use of IV inotropic therapy. ( 4 ) Severe hepatic impairment. ( 2.4 , 4 ) History of serious hypersensitivity reaction (e.g., Stevens-Johnson syndrome, anaphylactic reaction, angioedema) to any component of this medication or other medications containing carvedilol. ( 4 ) Carvedilol tablets are contraindicated in the following conditions: Bronchial asthma or related bronchospastic conditions. Deaths from status asthmaticus have been reported following single doses of carvedilol tablets. 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 carvedilol tablets. 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.

Pregnancy and Breastfeeding

8.1 Pregnancy Risk Summary Available data regarding use of carvedilol 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...

8.2 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 carvedilol and any potential adverse effects on the breastfed infant from carvedilol or from the underlying maternal condition.

Overdosage

10 OVERDOSAGE 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 carvedilol tablets 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.

How Supplied

16 HOW SUPPLIED/STORAGE AND HANDLING Carvedilol Tablets USP, 3.125 mg are white to off-white, round, biconvex, film-coated tablets debossed with 'Z' on one side and '1' on other side and are supplied as follows: NDC-42708-181-60 in bottles of 60 tablets Storage Store at 20°C to 25°C (68°F to 77°F) [See USP Controlled Room Temperature]. Protect from moisture. Dispense in a tight, light-resistant container.