Trimipramine and other antipsychotics inhibit Campylobacter pylori in vitro.

A series of conventional anti-ulcer drugs, tricyclic antidepressants and neuroleptics (and some CNS non-active isomers) were tested in vitro for possible inhibition of Campylobacter pylori. These bacteria are claimed to play an etiological role in peptic ulcer disease, at least in gastritis B. While cimetidine, famotidine, ranitidine and pirenzepine were inactive, all the antipsychotic agents and their isomeric derivatives were active to various degrees with IC50 of 26-59 microM. Of special interest is trimipramine (Surmontil) that has been demonstrated to be effective against duodenal ulcers in some trials. The activity of the non-neuroleptic stereo-isomers of clopenthixol and chlorprothixene may lead to investigation in patients with peptic ulcer disease of this kind of agents. However, a firm connection between the antimicrobial activity of these compounds, their possible anti-ulcer effect and the etiological role of Campylobacter pylori in peptic ulcer disease must first be established.