Prescription weight loss pill use among Americans: patterns of pill use and lessons learned from the fen-phen market withdrawal

Background: Despite the popularity of antiobesity medications, there is a lack of population-based data on their use. In addition, response (termination of pill use and receipt of an echocardiogram) to the fenfluramine and dexfenfluramine market withdrawal among the public has not been described. Lessons learned from this event have implications for future withdrawals. Methods: We used data from the Behavioral Risk Factor Surveillance System (BRFSS) a random-digit telephone survey. In 1998, six states included detailed questions about the use of prescription weight loss pills in the previous 2 years, n = 16,460 noninstitutionalized adults aged 18 years or older. Results: Almost one third of prescription weight loss pills users were not obese before taking pills. Family and friends and other nonphysicians were reported as sources of medication by one in ten users. One third of users also reported taking nonprescription diet products. Among fenfluramine or dexfenfluramine users, one third continued pill use after the market withdrawal and only one quarter received echocardiograms. Conclusions: Despite enormous publicity, many persons continued to use fen-phen after the market withdrawal and most did not receive follow-up echocardiograms. Our study raises issues regarding the effectiveness of withdrawal warnings in a small but significant subset. Additional means of communicating risk to individuals are needed for future product withdrawals including special strategies for those lacking healthcare coverage.