OCPs are C/I in pts receiving:
Ans. is a, i.e. RifampicinRef: KDT 6th/ed, p317; Novak 14th/ed, p276Interactions of OCPs with other Drugs.Effect of other drugs on OCP's:Drugs reducing the effectiveness of OCPDrugs which increase the plasma level of steroids of OCP* RifampicinQ* CarbamazepineQ* Phenytoin* Ascorbic acid* Acetaminophen* Antifungals like- Griseofulvin- Ketoconazole- ItraconazoleInduce synthesis of cytochromeP450 enzymes in liver.* Ampicillin* TetracyclineKill gut bacteria and cause hydrolysis of steroid glucuronides in intestine.
Rifampicin
Ethambutol
Streptomycin
Pyrazinamide
Contraceptives