1984 Volume 9 Issue SupplementI Pages 13-28
The effects of ranitidine hydrochloride, a histamine H2-receptor antagonist, on the reproductivity of male and female rats of Crj : CD (SD) strain and the development of their fetuses were examined. Ranitidine hydrochloride was intravenously administered once daily at dose levels of 5, 15 and 40 mg/kg in base weight respectively, to males from 60 days before mating until the completion of mating, and to females from 14 days before mating up to day 7 of gestation. All pregnant females were killed on day 20 of gestation and their fetuses were examined morphologically. Tachypnea, prone position and transient tremor were observed for a short period of time directly after an intravenous administration of ranitidine in the dose of 40 mg/kg, which were probably induced by a rapid fall in blood pressure. There was a significant decrease in the weight of spleen in males of 15 and 40 mg/kg groups. Treatment with ranitidine hydrochloride did not have any influence on mating performances and pregnancy at all dose levels. In observation of the fetuses, there was no influence of ranitidine hydrochloride administration on fetal growth and development. A few external, skeletal and visceral malformations were seen sporadically in each group, and 19 cases of dwarf fetuses were observed in 2 dams of 40 mg/kg group, but these changes were not attributable to administration of the drug. These results indicated that ranitidine hydrochloride intravenously administered to males and females before mating and to pregnant females in early stages of gestation had no toxic effects on reproductivity in either sex at the dose of 40 mg/kg/day or less.
