Toxicological and teratological studies of 2-chloro-11-(2-dimethylaminoethoxy)-dibenzo[b,f]thiepine (zotepine), a new neuroleptic drug.

: Toxicological and teratological studies of 2-chloro-11-(2-dimethylaminoethoxy)dibenzo[b,f]thiepine (zotepine) were performed in mice, rats, rabbits and dogs. There was no essential difference among mice, rats, rabbits and dogs in the acute toxicity of i.v. given zotepine. The rather small variation between intravenous and oral acute toxicity suggests the good absorption of zotepine from the gastrointestinal tract. In the subacute and chronic toxicity studies in rats, significant changes attributed to the drug were impairment of growth, alveolar proliferation in the mammary gland, decrease in uterine weight and increased number of diestrous rats. These changes were dose-dependent in the animals given 16 mg/kg or higher. Incidence of tumor in the treated groups in the 12-month study was almost the same as that in the control. In the subacute and chronic toxicity studies in dogs, abnormal quietness and abnormal gait occurred. Enlarged breasts and galactorrhea also occurred in females given 16 and 64 mg/kg in the 6-month study. Apart from these changes, one dog given 64 mg/kg had reversible hepatic dysfunction. In the teratological studies, zotepine had no adverse effects on pregnant animals and their fetuses in rats and rabbits, or reproductive performance of the F1 rats.