Effect of clindamycin on intestinal water and glucose transport in the rat.

Clindamycin therapy occasionally results in pseudomembranous colitis but more often results in a watery diarrheal syndrome which usually stops on cessation of clindamycin. This study was done to determine whether clindamycin itself might alter intestinal water, electrolyte, and glucose transport in the rat. The in vivo single-pass perfusion method was used. Perfusion with clindamycin altered intestinal water and electrolyte transport in a dose-related manner. Glucose transport was unaffected. Different segments of the intestine revealed a varying sensitivity to clindamycin: ileum greater than jejunum greater than colon. The transport defect was reversible on cessation of clindamycin perfusion. Chronic exposure of the intestine to clindamycin did not result in any alterations in water transport. The mechanism by which clindamycin causes these transport defects is unknown but did not involve the cyclic AMP or cyclic GMP systems, increased mucosal permeability, or alterations of mucosal morphology. The findings that clindamycin markedly inhibits intestinal water transport and induces net secretion in the ileum may explain the reversible watery diarrhea that many patients experience when treated with clindamycin.