Cimetidine inhibition of dimaprit-induced writhing in the rat

Intraperitoneal, but not intravenous administration of dimaprit (50-125 mg/kg) caused a dose-dependent writhing in the rat. This effect was blocked, again in a dose-dependent fashion, by cimetidine administered orally 1 h prior to dimaprit. Results obtained suggest that dimaprit induces a cimetidine-sensitive pain by acting at peripheral nociceptive terminals within the peritoneum. The specific (H2-receptor related) analgesic effect of cimetidine could explain its effectiveness in relieving epigastric pain of duodenal ulcer patients treated with the drug.