Teratogenicity of cyproheptadine in pregnant rats.

The teratogenicity of cyproheptadine HCL (Periactin) was studied in 3 groups of pregnant rats which received respectively 0.5 mg/kg/day, 2.5 mg/kg/day and 5 mg/kg/day cyproheptadine subcutaneously and in a control group of pregnant rats which received 0.2 ml/day of the solvent normal saline. Higher doses were toxic to pregnant rats. There was no significant difference in the birth rate, foetal resorption rate and malformation rate between the 4 groups. Moreover, there was no significant difference between average weights, average foetal placental weights and male/female ratio in the experimental and control foetuses. It is concluded that cyproheptadine is devoid of any teratogenic effect in rats.