Calcium channel blockers are inferior to less expensive antihypertensives in preventing cardiovascular complications of high blood pressure, according to a review by US researchers.

The review, presented at the recent European Society of Cardiology's meeting in Amsterdam, analysed the results of nine randomised clinical trials that compared long-acting calcium channel blockers with other antihypertensives such as diuretics, beta-blockers and angiotensin converting enzyme (ACE) inhibitors. Calcium channel blockers typically cost over 10 times more than older antihypertensives such as diuretics.

The review found calcium channel blockers were as effective as other antihypertensives at lowering blood pressure. But they failed to provide the additional protection that cheaper antihypertensives did in preventing heart attack and congestive heart failure.

In patients treated with calcium channel blockers, the risk of a heart attack was 27 per cent higher, the risk of heart failure was 26 per cent higher and the risk of any major cardiovascular event was 11 per cent higher. The review was based on data from more than 25,000 patients.

Patients taking intermediate and long-acting calcium channel blockers accounted for almost 13,000 patients.

A study published last year showed calcium channel blockers were not as effective in elderly patients with diabetes and systolic hypertension (New England Journal of Medicine, March 4 1999, p677).