Left Ventricular Dysfunction Following Myocardial Infarction: Carvedilol tablets have been evaluated for safety in survivors of an acute myocardial infarction with left ventricular dysfunction in the CAPRICORN trial which involved 969 patients who received carvedilol tablets and 980 who received placebo. Approximately 75% of the patients received carvedilol tablets for at least 6 months and 53% received carvedilol tablets for at least 12 months. Patients were treated for an average of 12.9 months and 12.8 months with carvedilol tablets and placebo, respectively.
The following adverse events were reported with a frequency of >1% but ≤3% and more frequently with carvedilol tablets: 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 patients. In this database, the only cause of discontinuation >1%, and occurring more often on carvedilol was hypotension (1.5% on carvedilol, 0.2% on placebo).
Hypertension: Carvedilol has been evaluated for safety in hypertension in more than 2,193 patients in US clinical trials and in 2,976 patients in international clinical trials. Approximately 36% of the total treated population received carvedilol tablets for at least 6 months. Most adverse events reported during therapy with carvedilol tablets were of mild to moderate severity. In US controlled clinical trials directly comparing carvedilol tablets in doses up to 50 mg (n = 1,142) to placebo (n = 462), 4.9% of patients receiving carvedilol tablets discontinued for adverse events versus 5.2% of placebo patients. 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 US placebo-controlled trials increased with increasing dose of carvedilol tablets. 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 US placebo-controlled clinical trials for hypertension that occurred with an incidence of ≥1% regardless of causality, and that were more frequent in drug-treated patients than placebo-treated patients.
Table 2. Adverse Events (%) Occurring in US Placebo-Controlled Hypertension Trials (Incidence ≥1%, Regardless of Causality)*Shown are events with rate >1% rounded to nearest integer.
| Carvedilol Tablets | Placebo |
|---|
| (n = 1,142) | (n = 462) |
|---|
| Cardiovascular | | |
| Bradycardia | 2 | — |
| Postural hypotension | 2 | — |
| Peripheral Edema | 1 | — |
| Central Nervous System | | |
| Dizziness | 6 | 5 |
| Insomnia | 2 | 1 |
| Gastrointestinal | | |
| Diarrhea | 2 | 1 |
| Hematologic | | |
| Thrombocytopenia | 1 | — |
| Metabolic | | |
| Hypertriglyceridemia | 1 | — |
Dyspnea and fatigue were also reported in these studies, but the rates were equal or greater in patients who received placebo.
The following adverse events not described above were reported as possibly or probably related to carvedilol tablets in worldwide open or controlled trials with carvedilol in patients with hypertension.
Incidence >0.1% to ≤1%
Cardiovascular: Peripheral ischemia, tachycardia.
Central and Peripheral Nervous System: Hypokinesia.
Gastrointestinal: Bilirubinemia, increased hepatic enzymes (0.2% of hypertension patients were discontinued from therapy because of increases in hepatic enzymes) [see Adverse Reactions (6.2)].
Psychiatric: Nervousness, sleep disorder, aggravated depression, impaired concentration, abnormal thinking, paroniria, emotional lability.
Respiratory System: Asthma [see Contraindications (4)].
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 ≤0.1% of patients 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.
Left Ventricular Dysfunction Following Myocardial Infarction: The basis for the beneficial effects of carvedilol 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 carvedilol tablets are administered with food at the recommended starting dose and titration increments are closely followed [see Dosage and Administration (2)].
In hypertensive patients with normal renal function, therapeutic doses of carvedilol 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 carvedilol and placebo.
Carvedilol 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.
Geriatric: Plasma levels of carvedilol average about 50% higher in the elderly compared to young subjects.
Hepatic Impairment: Compared to healthy subjects, patients with severe liver impairment (cirrhosis) exhibit a 4- to 7-fold increase in carvedilol levels. Carvedilol is contraindicated in patients with severe liver impairment.
Renal Impairment: Although carvedilol is metabolized primarily by the liver, plasma concentrations of carvedilol have been reported to be increased in patients with renal impairment. Based on mean AUC data, approximately 40% to 50% higher plasma concentrations of carvedilol were observed in hypertensive patients with moderate to severe renal impairment compared to a control group of hypertensive patients with normal renal function. However, the ranges of AUC values were similar for both groups. Changes in mean peak plasma levels were less pronounced, approximately 12% to 26% higher in patients with impaired renal function.
Consistent with its high degree of plasma protein-binding, carvedilol does not appear to be cleared significantly by hemodialysis.
Cimetidine:In a pharmacokinetic study conducted in 10 healthy male subjects, cimetidine (1,000 mg/day) increased the steady-state AUC of carvedilol by 30% with no change in Cmax [see Drug Interactions (7.5) ].
Digoxin:Following concomitant administration of carvedilol (25 mg once daily) and digoxin (0.25 mg once daily) for 14 days, steady-state AUC and trough concentrations of digoxin were increased by 14% and 16%, respectively, in 12 hypertensive patients. [see Drug Interactions (7.4)].
Glyburide:In 12 healthy subjects, combined administration of carvedilol (25 mg once daily) and a single dose of glyburide did not result in a clinically relevant pharmacokinetic interaction for either compound.
Hydrochlorothiazide:A single oral dose of carvedilol 25 mg did not alter the pharmacokinetics of a single oral dose of hydrochlorothiazide 25 mg in 12 patients with hypertension. Likewise, hydrochlorothiazide had no effect on the pharmacokinetics of carvedilol.
Rifampin:In a pharmacokinetic study conducted in 8 healthy male subjects, rifampin (600 mg daily for 12 days) decreased the AUC and Cmax of carvedilol by about 70% [see DrugInteractions (7.5)].
Torsemide: In a study of 12 healthy subjects, combined oral administration of carvedilol 25 mg once daily and torsemide 5 mg once daily for 5 days did not result in any significant differences in their pharmacokinetics compared with administration of the drugs alone.
Warfarin: Carvedilol (12.5 mg twice daily) did not have an effect on the steady-state prothrombin time ratios and did not alter the pharmacokinetics of R(+)- and S(-)-warfarin following concomitant administration with warfarin in 9 healthy volunteers.