The effects of loperamide on continence problems and anorectal function in obese subjects taking orlistat.

Continence problems during treatment with orlistat (a lipase inhibitor) are caused when susceptible patients are exposed to increased volumes of loose, fatty stool.

OBJECTIVE

To investigate the dose-response effects of loperamide on continence and anorectal function in subjects susceptible to continence problems on orlistat.

METHODS

Ten obese subjects enterred a randomized controlled, double-blind study of loperamide at placebo, 2, 4, and 6 mg/day in a factorial design. Continence problems during orlistat treatment were self-assessed by patient diary. Anorectal function and continence were assessed by barostat, manometry, and retention testing.

RESULTS

Loperamide increased stool consistency with dose (p = 0.07) and this effect reduced continence problems during orlistat treatment (p < 0.05). A bell-shaped dose-response relationship was present with anal sphincter function (p < 0.01) and anorectal sensitivity (p < 0.01).

CONCLUSIONS

Loperamide has beneficial effects on stool consistency and continence in obese subjects taking orlistat. The effect on stool consistency appeared more important than effects on anorectal function.