Calcium Channel Blocker Debate Continues

The publication of a meta-analysis on the safety of the calcium channel blocker nifedipine in the September 1 issue of Circulation has, like the article in the Journal of the American Medical Association before it (Marketletter September 4), reignited the heated debate on the role of these drugs in patients with heart disease and high blood pressure.

The new study was authored by Curt Furberg of the Bowman Gray School of Medicine in Winston-Salem, North Carolina, and co-authored by Bruce Psaty of the University if Washington in Seattle (who conducted the JAMA analysis). The analysis of 16 randomized secondary prevention trials suggested that in coronary disease patients, short-acting nifedipine use in moderate to high doses causes an increase in total mortality. Doses of nifedipine which were greater than 60mg/day almost tripled the risk of death compared to placebo, said the report.

Immediate-release nifedipine is marketed in the USA by Pfizer (Procardia) and Bayer (Adalat), but it is generally accepted that these agents are no longer widely-used because of a wholesale shift to the more convenient sustained-release forms.