Questions about most-prescribed blood pressure med

A meta-analysis published in the Journal of the American College of Cardiology indicates that the world’s most widely prescribed blood pressure medication, hydrochlorothiazide, is only a little more than half as effective in treating high blood pressure as newer classes of drugs like ACE inhibitors and calcium channel blockers.

While over a 24-hour period ACE (angiotensin converting enzyme) inhibitors were shown to reduce patients’ systolic or “top” blood pressure by 12.9 points on average and calcium channel blockers by 11.2 points, hydrochlorothiazide only produced a drop of 6.5 points.

Hydrochlorothiazide is one of an older class of diuretic hypertension medications called thiazides that are currently recommended as the first-line of treatment to lower high blood pressure. The study’s researchers did not examine the data for related drugs in the thiazide family like chlorthalidone or indapamide.

Their report, however, appears to contradict current government recommendations which grew out of research done more than a decade ago suggesting that other thiazides were as effective as newer and more expensive drugs like the ACE inhibitors and calcium channel blockers.

ACSH’s Dr. Gilbert Ross says that we would do best not to write off hydrochlorothiazide though, commenting that, “A reduction in systolic blood pressure of 6.5 mm is not trivial even if inferior to that affected by other classes of drugs. But the widespread use of hydrochlorothiazide alone after the late-90s study showing thiazides were at least as effective as the more expensive drugs seems to have been too rapid a change in prescribing habits and should now be reconsidered.”