A U.S. study has determined the first of a new class of drugs designed to treat hypertension has limited effectiveness.

There are currently seven classes of drugs used to reduce blood pressure. Aliskiren (Tekturna and Rasilez) is the first of a new class of orally active anti-hypertensive drugs that works by inhibiting the enzyme rennin that can raise blood pressure.

But a review of six large-scale clinical trials of aliskiren by Jean Sealey and Dr. John Laragh of the Weill Cornell Medical College found, because of reactive renin secretion, the drug has not been any more effective than those already widely available to control hypertension.

Laragh and Sealey found in analyzing clinical trials involving more than 5,000 hypertensive patients, aliskiren was no more effective as an anti-hypertensive agent than converting enzyme inhibitors, angiotensin receptor blockers or diuretics.

The research is detailed in the May issue of the American Journal of Hypertension.

Copyright 2007 by United Press International