<prompt> Which of the following causes OCP failure?CarbamazepineRifampicinNSAIDSEthambutol  <response>: 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 