Parkinson's Disease Health Center

Parkinson's Drugs: Heart Damage Link?

Important Mechanism

Bryan Roth, MD, PhD, tells WebMD that the two Parkinson's drugs appear to cause heart damage in the same way that the now notorious weight loss medication fen-phen did.

Fen-phen was voluntarily withdrawn from the market a decade ago, following reports of life-threatening heart valve disease. Another related diet drug marketed by Wyeth-Ayerst Laboratories as Redux was also withdrawn.

The diet drugs and their byproducts have been shown by Roth and others to selectively bind to specific receptors in human heart valve cells, known as 5-HT2B. The same mechanism was seen in the two implicated Parkinson's drugs.

"The two new studies provide the best evidence yet for validating this particular mechanism," Roth tells WebMD. "5-HT2B receptor activity predicts heart valve disease."

Roth, who is a professor of pharmacology at the University of North Carolina School of Medicine, Chapel Hill, says all investigational drugs and byproducts should be screened for 5-HT2B activity in the future.

In an editorial published along with the two studies, Roth called on doctors to avoid prescribing the drugs.