<prompt> Oral contraceptive Pill OCP failure is seen with all except:RifampicinPhenobarbitoneValproatePhenytoin  <response>: Drugs leading to OCP failure are: Rifampicin Tetracyclines Phenytoin Phenobarbitone Antifungals Cephalosporin Ritonavir for HIV interferes with absorptionn of OCP Ref: online resources ncb.nlm.nih.gov 