Effect of diazepam and phenobarbital sodium on postcoital contraceptive efficacy of ethinyl estradiol in rats.
Diazepam, a well known tranquilizer, and ethinyl estradiol have frequently been prescribed together in rape cases. These two drugs were reported to possess an opposite action on uterine motility. Phenobarbital, a typical enzyme inducer, has been prescribed together with ethinyl estradiol in some cases as a sedative-hypnotic. The present study was, therefore, designed to investigate the possible interferences of diazepam or phenobarbital sodium on postcoital contraceptive efficacy of ethinyl estradiol (4 micrograms/kg/day) in rats. All tested doses of diazepam (1, 2 and 4 mg/kg/day) or phenobarbital sodium (30 and 60 mg/kg/day) appear to have no effect on the efficacy of ethinyl estradiol when either of them was administered from D3 to D5 or from D1 to D5 of pregnancy. In addition, neither diazepam nor phenobarbital sodium at the highest doses used showed an effect on pregnancy.
D000818:Animals; D003281:Contraceptives, Postcoital; D003975:Diazepam / Q000494:pharmacology*; D004347:Drug Interactions; D010064:Embryo Implantation / Q000187:drug effects; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000494:pharmacology; D005260:Female; D010634:Phenobarbital / Q000494:pharmacology*; D011247:Pregnancy; D051381:Rats; D014590:Uterine Contraction / Q000187:drug effects
D003281:Contraceptives, Postcoital; D004997:Ethinyl Estradiol; D003975:Diazepam; D010634:Phenobarbital