Which does not effect metabolism of oral contraceptive pill ?: (A) Phenytoin, (B) Gresiofulvin, (C) Primidone, (D) Penicillin
Answer is D. Ans. is d i.e., Penicillin Contraceptive failure may occur if the following drugs are given concurrently : a) Enzyme inducer - Enhances the metabolism of estrogen & progesterone. Phenytoin Carbamazepine Primidone Phenobarbitone Rifampicin Griseofulvin b) Suppression of intestinal microflora - enterohepatic circulation. Tetracyclines Ampicillin