Toxicity studies on lidamidine hydrochloride (WHR-1142A), a novel antidiarrheal agent.

The acute oral LD50 of 1-(2,6-dimethylphenyl)-3-amidinourea hydrochloride (WHR-1142A, lidamidine hyrochloride) was 260 (208, 328) mg/kg in male mice, 267 (212, 336) mg/kg in male rats and 160 (130, 197) mg/kg in female rats. A daily oral dose of 10 mg/kg for 30 days was well tolerated in the rat and monkey. Histologic changes were reversible and for the most part could be explained on the basis of one or more of the several pharmacologic effects of WHR-1142A. A short-lived hyperglycemic effect was a prominent effect in mice and rats. This effect was seen occasionally in high doses in the monkey, suggesting a species difference.