A comparative review of the adverse effects of calcium antagonists

A large number of drugs within the 3 currently classes of calcium antagonists are in common medical use for the treatment of hypertension and ischaemic heart disease. The reported adverse effect profile for each of these drugs varies, but tends to hold true to drug class and are typified by the adverse reactions reported for nifedipine and amlodipine (dihydropyridines), diltiazem (benzothiazepines) and verapamil (phenylalkylamines). Minor adverse effects such as flushing, headache, ankle oedema, palpitations and constipation are not uncommon and frequently require the cessation of treatment. Of greater concern affecting the wide and common first-line use of calcium antagonists is the as-yet unresolved issue of a reportedly greater risk of myocardial infarction and death following the use of short-acting nifedipine in patients with a history of hypertension, myocardial infarction or angina. Until this issue is fully resolved, it would seem prudent to limit the use of this agent in 'at-risk' patients and to await the results of further prospective studies before a final conclusion can be made.