Similarities and differences between calcium antagonists: pharmacological aspects.

Characteristics of three different calcium antagonist groups: Most important calcium antagonists used to treat cardiovascular disease belong to one of three main groups, phenylalkylamines, dihydropyridines and benzothiazepines. The best known drug in each group is verapamil, nifedipine and diltiazem, respectively. Dihydropyridines are predominantly vasodilators, with little or no primary cardiac activity; the tachycardia caused by these compounds is a reflex phenomenon. Verapamil and related drugs are also vasodilators, with an additional depressant effect on atrioventricular conduction, heart rate and contractility. Diltiazem's pharmacodynamic profile and side effects may be considered as intermediate between those of the dihydropyridines and verapamil. Characteristics of new calcium antagonists: Several new calcium antagonists have been introduced in the last few years, virtually all dihydropyridines. Compared with the older generation of calcium antagonists these newer drugs tend to have (1) a longer duration of action; (2) some selectivity for a specific vascular bed, such as resistance, coronary, renal or cerebral vessels; (3) a potentially useful extra component, such as diuretic or anti-atherogenic activity. Newer calcium antagonists described in this review: The newer compounds briefly characterized in this review are amlodipine, felodipine, isradipine, lacidipine, nimodipine, nisoldipine and nitrendipine. New slow-release formulations are also discussed. There is a particular emphasis on lacidipine and its potential for cardiovascular drug therapy.