Comparison of combinations of drugs for treatment of obesity: body weight and echocardiographic status

Background: Obesity treatment with single drugs produces weight losses of about 8-10% of initial body weight. Few studies of combinations of drugs for treating obesity have been published. The combination of phentermine, an adrenergic agent, and fenfluramine, a serotonergic agent, (phen-fen) produced weight losses of about 15% of initial body weight. Fenfluramine is no longer available because it was associated with cardiac valve lesions. Phentermine-fluoxetine (phen-flu) has been proposed as an alternative for phen-fen. Objective: To compare the efficacy of treatment and prevalence of cardiac valve abnormalities on phen-flu vs phen-fen. Design: Retrospective chart review of all patients treated for at least 3 months with phen-flu (N=97) to a random sample of patients treated with phen-fen (N=98) in the Clinical Nutrition Clinic at the University of Wisconsin. Comparison of echocardiograms in all patients treated solely with phen-flu (N=21) to a random sample of patients treated with phen-fen (N=47), and to a group of subjects never treated with obesity drugs (N=26). Results: With last observation carried forward analysis (LOCF), at 6 months of treatment the phen-fen patients lost 12.6+/-0.6% of baseline weight and phen-flu patients lost 9.00.6% (P