Which of the following causes OCP failure?: (A) Carbamazepine, (B) Rifampicin, (C) NSAIDS, (D) Ethambutol
Answer is B. ANSWER: (B) RifampicinREF: KDT 7th ed p. 317Contraceptive failure of OCP can occur if concurrently used with followingEnzyme inducers:By increase metabolism of OCRSSuppression of microbial flora: interfere with enterohepatic circulation* Phenytoin* Phenobarbitone* Primidone* Carbamezapine* Rifampidn* Tetracyclines* Ampiciliins