Comparative Evaluation of Fecal Fat Excretion Induced by Orlistat and Chitosan

OBJECTIVE: To compare the effects of chitosan and orlistat on fecal fat excretion. RESEARCH METHODS AND PROCEDURE: A randomized, open-label, two-period sequential design study was used. A total of 12 healthy adult volunteers within 20% of their ideal body weight entered a 7-day run-in diet period before being randomized to orlistat (120 mg) or chitosan (890 mg) three times daily for 7 days. Subjects then crossed over treatment regimens for an additional 7-day period. Subjects followed a standardized diet (2500 kcal/d, 30% as fat) for the entire 21-day study. Feces were collected on days 4 to 7 of the run-in period (baseline) and during the two treatment periods. Mean daily fecal fat excretion was measured at baseline and during each treatment regimen. RESULTS: Mean baseline fecal fat excretion for all subjects was 1.36 +/- 0.45 g/d. During orlistat treatment, mean fecal fat excretion significantly increased from baseline (+16.13 +/- 7.27 g/d; p < 0.001). No significant effect was observed with chitosan (+0.27 +/- 1.02 g/d; p = 0.379). Fecal fat excretion was significantly greater with orlistat than with chitosan (p < 0.001; 95% confidence intervals: 11.73; 20.00 g/d). DISCUSSION: This study provides additional evidence of the inhibitory effect of orlistat on dietary fat absorption. Chitosan, however, has no effect on fecal fat excretion.