COREG 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 COREG for at least 6 months. Most adverse events reported during therapy with COREG were of mild to moderate severity. In US controlled clinical trials directly comparing COREG in doses up to 50 mg (n = 1,142) to placebo (n = 462), 4.9% of patients receiving COREG 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 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 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)* | COREG | 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 | — |
* Shown are events with rate >1% rounded to nearest integer.
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 COREG in worldwide open or controlled trials with COREG in patients with hypertension or heart failure.
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 and 0.4% of heart failure 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.
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. Significantβ-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 [see Dosage and Administration (2)].
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.