Amlodipine: a new calcium antagonist.
The chemistry, pharmacology, pharmacokinetics, efficacy, and adverse effects of amlodipine are reviewed. Amlodipine belongs to the dihydropyridine subclass of calcium antagonists. Amlodipine is a potent peripheral and coronary vasodilator with high selectivity for vascular smooth muscle and minimal effect on myocardial contractility or cardiac conduction. Absorption after oral administration is slow, and the duration of action is long, with a half-life of 36-45 hours. Amlodipine has FDA-approved labeling for use in the treatment of hypertension, chronic stable angina, and vasospastic angina. The agent is also indicated for use in hypertensive or anginal patients who also have congestive heart failure due to systolic dysfunction (New York Heart Association classes II and III). Clinical trials suggest that effective 24-hour control of hypertension and angina is provided by once-daily administration of amlodipine 5-10 mg alone or in combination with other drugs. No clinically important drug interactions have been observed to date. Amlodipine has not shown any unfavorable effects on serum glucose or lipid levels. The most common adverse effect is peripheral edema. Amlodipine is effective and well tolerated when given alone or in combination with other drugs for the treatment of hypertension and angina. Amlodipine may offer advantages over verapamil, diltiazem, and nifedipine in patients with hypertension or angina with associated congestive heart failure due to systolic dysfunction.