It was once suggested that calcium channel blockers might be dangerous for treating hypertension. Is this still true?

Innumerable editorials, reviews and letters have been written on the calcium channel blocker controversy that started with the publication of the case-control study by Psaty et al in 19951 and the subsequent meta-analysis of Furberg et al in the same year.2 They reported a greater increase in the risk of myocardial infarction among those taking short-acting calcium channel blockers than amongst those taking diuretics or beta-blockers. The risk was greatest at higher doses of nifedipine. Other concerns relate to an increase in gastrointestinal haemorrhage, bleeding in relation to surgery and cancer. Since then three further case-control studies have not found an association between calcium channel blockers and adverse cardiovascular outcome, while a leash of prospective trials have added greatly to the quality of the data available on this issue. There is general consensus that short-acting dihydropyridines should not be given to patients with ischaemic heart disease. The position in hypertension is less clear. There do seem to be grounds for concern about short acting dihydropyridines relative to other treatments. The recent case-control studies do not seem to raise the same concerns with long-acting agents, at least from the point of view of adverse cardiovascular outcomes. However, the real safety profile of these agents in hypertension will not be known until many ongoing prospective randomised trials such as ALLHAT report.3 Despite the absence of these trials a prudent interim approach would be to restrict the use of calcium antagonists to the newer slow-release formulations that, by virtue of their ability to attain more gradual and sustained plasma levels, do not evoke a reactive sympathetic activation.