Which of the following proton pump inhibitor has enzyme inhibitory activity: (A) Rabeprazole, (B) Lansoprazole, (C) Pantoprazole, (D) Omeprazole
Answer is D. Omeprazole inhibits oxidation of certain drugs like diazepam, phenytoin and warfarin levels may be increased. Clarithromycin inhibits omeprazole metabolism and increases its plasma concentration.