Parkinson's Drugs: Heart Damage Link?
Researchers Raise Concerns About Damage to Heart Valves From 2 Parkinson's Drugs
WebMD News Archive
Checking for Heart Valve Disease continued...
Clinically important evidence of valve damage was seen in roughly 5% of the
comparison group, compared with 23% of patients taking pergolide and 28% of
patients taking cabergoline.
Garbe says it is clear from the two studies that patients taking either
pergolide or cabergoline should be monitored closely for heart valve
"We aren't saying that these drugs should not be used," she says.
"I think if patients are appropriately followed they can be prescribed. But
neurologists and other treating physicians have to be made aware of the
A spokesman for pergolide manufacturer Valeant Pharmaceuticals International
tells WebMD that the company would have no direct comment on the two new
studies. But a company statement reaffirmed the safety of the drug.
"Permax (pergolide) is a safe and effective treatment for patients with
Parkinson's disease," the statement reads. "Although Valeant no longer
promotes the product, we still make it available for those who prescribe it. We
also routinely communicate with the FDA and recently worked with the agency to
modify the label to advise physicians that the product, like other dopamine
agonists, should be used with caution."
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Fen-phen was voluntarily withdrawn from the market a decade ago, following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marketed by Wyeth-Ayerst Laboratories as Redux was also withdrawn.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
"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.