Drugs Control Blood Pressure

A new, experimental class of drugs appears to be the most potent ever at reducing high blood pressure.

Doctors said Monday that the first of these medicines to reach large-scale testing outperformed two mainstays of blood pressure control, a top-selling ACE inhibitor and a calcium-channel blocker.

The new medicines are called vasopeptidase inhibitors. Several are in development, but the furthest along is Bristol-Myers Squibb's Vanlev, known generically as omapatrilat.

Researchers released results of Vanlev's testing Monday at a company-sponsored session held in conjunction with an American Heart Association meeting in Atlanta.

Bristol-Myers Squibb said it plans to seek permission from the Food and Drug Administration by the end of the year to sell Vanlev.

The main categories of blood pressure drugs are angiotensin converting enzyme inhibitors (or ACE inhibitors), beta blockers, calcium channel blockers, diuretics and angiotensin receptor blockers.

Like standard ACE inhibitors, the vasopeptidase inhibitors block angiotensin converting enzyme, which raises blood pressure. However, the medicine also stops another enzyme called neutral endopeptidase. By doing this, the medicine protects the body's supply of other helpful substances that make blood vessels relax and prevent dangerous overgrowth of heart muscle.

"It's the most powerful oral drug that we have ever had available," said Dr. Michael A. Weber of Brookdale University Hospital in New York City.

Studies by Weber and others compared Vanlev with Zestril, the best-selling ACE inhibitor, and Norvasc, the top calcium channel blocker.

Vanlev appeared to do a better job of lowering both systolic and diastolic pressure. Systolic is the pressure in the arteries when the heart beats. Diastolic is the pressure between beats. Systolic is the first and larger of the two numbers. Ideal blood pressure is less than 140 over 90.

The comparison with Zestril was conducted on 347 volunteers. Vanlev lowered systolic nine points and diastolic five points better than Zestril.

Vanlev was compared with Norvasc on 430 people. It lowered both systolic and diastolic pressure five points better.

Many people with hypertension need to take more than one medicine to bring their blood pressure under control. Weber said Vanlev alone should be able to do this for about half of all patients. Most other drugs are enough for about one-third of patients.

Dr. Henry R. Black of Rush-Presbyterian-St. Luke's Medical Center in Chicago said doctors now realize that bringing down systolic pressure is especially important, even though it was long ignored.

Vanlev's "particular attraction for me is it seems to be considerably more effective than what we already have for lowering systolic blood pressure. I don't know why that is, but it's the case," Black said. He participated in earlier testing of Vanlev but was not involved in th latest studies.

Written by Daniel Q. Haney