<prompt> Which of the following is P-Glycoprotein inhibitorRifampicinPhenytoinGriseofulvinKetoconazole  <response>: Drugs like cyclosporine, tacrolimus, quinidine, diltiazem, verapamil, itraconazole, ketoconazole, amiodarone inhibit P-Glycoprotein and cause drug toxicity. 