The "phen-pro" combination of phentermine (30 mg) and fluoxetine hydrochloride (10 or 20 mg), a well-known alternative to the "phen-fen" diet drug combination, has gained greater currency since fenfluramine hydrochloride and dexfenfluramine hydrochloride were withdrawn from the US market. Fenfluramine and dexfenfluramine have been associated with aortic and mitral valve regurgitation.1 Asymptomatic valve lesions occur in as many as 45% of patients taking phen-fen.2 It is unknown how many of these patients will progress to the symptomatic state.
Griffen L, Anchors M. The "Phen-Pro" Diet Drug Combination Is Not Associated With Valvular Heart Disease. Arch Intern Med. 1998;158(11):1278-1279. doi: