Clinical studies with phenylpropanolamine: a metaanalysis.

The combined analysis of parallel double-blind studies of prescription anorectic drugs in 1973 showed 0.23 kg/wk more weight loss than placebo at the end of the studies. In 1985, the combined studies of phenylpropanolamine (PPA) and PPA with caffeine gave 0.27 kg/wk more weight loss than placebo, but since 1985, this difference has dropped to 0.14 kg/wk in the combined studies with PPA. The incidence of adverse reactions in the combined studies with PPA were 19% and 14% for placebo (P less than 0.02). These adverse reactions were mild, however, and ceased with drug discontinuation. The two nonprescription anorectic drugs, PPA and benzocaine, and their combination, were compared in a 40-patient study. Benzocaine gave less weight loss than PPA (P less than 0.05 ANOVA). Thus, PPA is safe and effective for weight loss, appears less effective than prescription anorectics in studies exceeding 4 wk, and weight loss was not enhanced by combination with benzocaine.

RCT Entities:   Population Interventions Outcomes