Histologic changes in the guinea pig gastrointestinal tract following 1 weeks' administration of chlorpromazine, haloperidol or atropine.

A comparison was made between the toxic effects of chronic chlorpromazine, haloperidol or atropine on the guinea pig intestinal tract. Chlorpromazine, administered at a dose of 30 mg/kg/day, IP for 7 days, produced marked pathologic changes in the guinea pig cecum, consisting of inflammation, edema and hemorrhage. None of these effects were noted when haloperidol, 2 or 10 mg/kg/day or atropine 30 mg/kg/day were similarly administered. Similar toxic effects may occur in humans on long-term chlorpromazine or other phenothiazine therapy, thereby accounting for the paralytic ileus observed with these drugs.