Oral contraceptive Pill (OCP) failure is seen with all except:
High-Yield Explanation
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)