Dopamine Agonists and the Risk for Valvular Heart Disease

Fenfluramine and dexfenfluramine are serotonin-receptor (5-hydroxytryptamine [5-HT]) agonists that have been associated with valvular heart disease lesions similar to those induced by serotonin-secreting carcinoid tumors. Pergolide and cabergoline, ergot-derived dopamine agonists used to treat Parkinson disease, are potent 5-HT_2B–receptor agonists hypothesized to cause valvular heart disease. Two European studies test that hypothesis. (Note: cabergoline is not approved to treat Parkinson disease in some countries, including the U.S., but is used for other conditions.)

Using the U.K.'s General Practice Research Database, researchers identified 11,417 patients (age 40–80) who had been prescribed at least two antiparkinsonian drugs from January…