Plot thickens for blood pressure drugs. (Biomedicine).

Scientists reported last December that an inexpensive drug for hypertension, a diuretic, prevents heart failure and stroke better than newer, more costly blood pressure medicines do (SN: 1/18/03, p. 45). The findings prompted doctors to rethink treatments for some patients.

Not so fast. Researchers in Australia now report that one of the more costly drugs--a so-called angiotensin-converting-enzyme (ACE) inhibitor--prevents heart attacks and other heart problems better than a diuretic does. The study appears in the Feb. 13 New England Journal of Medicine.

The researchers tracked 6,083 people, ages 65 to 84, for 4 years. Half received an ACE inhibitor (most often enalapril) and half got a common diuretic (usually hydrochlorothiazide). During the study, 58 people in the ACE-inhibitor group had heart attacks, compared with 83 in the diuretic group. Also, volunteers in the ACE-inhibitor group were slightly less likely to die from any cause than were people getting the diuretic.

A closer look at the data reveals that ACE inhibitors protected men from heart problems better than diuretics did, but that women gained equal protection from the two drugs, report Christopher M. Reid of the Baker Heart Research Institute in Melbourne and his colleagues.

Differences between findings from this study and the one reported last December might result, in part, because the specific diuretics and ACE inhibitors were different in the two trials, says Edward D. Frohlich of the Alton Ochsner Medical Foundation in New Orleans. The first study tested the diuretic chlorthalidone against the ACE inhibitor lisinopril and amlodipine, a calcium-channel blocker.

A lesson of these studies, Frohlich says, is that rather than stampeding to one treatment or the other, doctors will need to tailor prescriptions to patients' individual needs.