Study Shows Lingering Heart Valve Problems in Former Users of Banned Obesity Drugs Fenfluramine and Dexfenfluramine

Two banned obesity drugs may have lingering effects on the heart, according to a new study.

The study shows that heart valve problems linked to the banned obesity drugs fenfluramine and/or dexfenfluramine typically last years after stopping those drugs.

The FDA ordered fenfluramine and dexfenfluramine off the market in September 1997 after those drugs were linked to heart valve problems. Fenfluramine was one of the ingredients in “fen-phen,” and dexfenfluramine is closely related to fenfluramine. The “phen” in fen-phen refers to a drug called phentermine, which wasn’t banned.

The new study, published online today in BMC Medicine, shows what happened to the hearts of 5,743 former users of fenfluramine and/or dexfenfluramine.

Heart Valve Problems

The patients were seen by doctors including Charles Dahl, MD, of the Central Utah Clinic in Provo, Utah, between July 1997 and February 2004.

During that time, each patient got an echocardiogram and 1,020 patients got two or more echocardiograms 30 months apart, on average.

Dahl’s team searched the echocardiograms for signs of blood leaking back through heart valves (regurgitation), and they noted which patients got surgery to correct heart valve problems.