The calcium channel antagonist debate: recent developments

Recent contributions to the calcium channel antagonist (CCA) debate concern the recommendations in the Sixth Report of the U.S.A. Joint National Committee on Prevention. Detection, Evaluation and Treatment of High Blood Pressure and raise questions about evidence-based medicine. Also, several studies have recently been published. A 4695-patient placebo-controlled trial showed that the CCA nitrendipine significantly reduces cardiovascular complications in older people with systolic hypertension. A 470-patient trial showed a significantly higher rate of myocardial infarction in hypertensive non-insulin-dependent diabetics treated with the CCA nisoldipine than in those treated with the ACE inhibitor enalapril. Non-experimental data (on 84 093 person-years in total) comparing antihypertensive agents in hypertensive women showed mostly non-significant covariate-adjusted total and cardiovascular mortality differences that are difficult to interpret because of potential residual confounding. One report suggested a relationship between CCAs and suicide. A case-control study (9513 cases, 6492 controls) showed that CCAs are unlikely to cause cancer. The current recommendation remains to start treatment of hypertension with diuretics and beta-blockers, but recent studies support the use of sustained release CCAs in cases in which blood pressure cannot be controlled with other agents.