Carvedilol is generally well tolerated, partly because of the combined alpha and beta blocking properties of the molecule allow clinical efficacy to be attained with lower dosages than might be required if it were a single-action drug. The most frequently reported adverse events in patients being treated with carvedilol are related to its vasodilatory (postural hypotension, dizziness and headaches) and β-blocking (dyspnea, bronchospasm, bradycardia, malaise and asthenia) properties. Adverse events are generally more common early in therapy, are dosage-related and appear to have a lower incidence than is seen with pure β-blockade.
The adverse events reported frequently with carvedilol in clinical trials in patients with congestive heart failure were hyperuricemia, hypoglycemia, hyponatremia, increased alkaline phosphatase, glycosuria, somnolence, impotence, abnormal renal function, and albuminuria.