Studies show little harm with banned weight loss drug

A study published in Tuesday's Annals of Internal Medicine looked at patients who took fenfluramine, the "fen" in the fen-phen cocktail. A second study, also published in the medical journal, dealt with people who took dexfenfluramine, a chemical cousin of fenfluramine.

The studies found that leaking heart valves got no worse with time and in some cases got better. A leaky valve makes the heart less efficient; severe leakage can cause heart failure.

The research mirrors the results of three previous studies.

The leader of the dexfenfluramine study, Dr. Neil Weissman of the Washington Hospital Center in Washington, D.C., said people with valve damage should be reassured by the findings.

"If you took diet pills and you (developed) a mild degree of (valve damage), it is unlikely that it will go on to become severe, and it is possible it may even get better," he said.

Researchers at Duke University Medical Center and MeritCare Medical Center in Fargo, N.D., looked at 50 people who took fenfluramine and had echocardiogram pictures of their heart taken at least 100 days apart. The first picture showed that 43 patients had damaged aortic valves. The second showed improvement in 19 patients and no change in 22 people. Two patients worsened.

Dr. Jack Crary, one of the study's authors and the first doctor to warn of possible heart damage from fen-phen, said the research confirms what he has seen in his practice.

"Most of them seemed to have improved in the short span of time we've looked at them."

In Weissman's study, researchers examined 914 patients who had either taken dexfenfluramine for up to three months or a placebo. The study found no evidence that the patients who developed valve problems got worse.

"These are two more important blocks in the foundation of our understanding of fenfluramine and its association with valvular heart disease," said Dr. Sid Smith, chief science officer of the American Heart Association, who was not involved with either study.

An Annals editorial said that while a study of the long-term effects of fen-phen is still needed, the new studies have "important clinical implications for management of patients in whom surgical intervention might otherwise be considered."

After a 1997 Mayo Clinic study showed heart valve damage in patients who took fen-phen, American Home Products pulled fenfluramine and dexfenfluramine from the market. The second drug in fen-phen, phentermine, was not linked to any problems.

American Home Products agreed last year to pay up to $3.75 billion in a proposed settlement that could cover all 6 million users of the drugs -- Pondimin and Redux.<