Immunosuppressant Agent Drug Interactions Calcineurin inhibitors:  cyclosporin or tacrolimus Increased CNI levels: allopurinol, azole antifungals, calcium channel blockers, colchicines, lansoprazole, macrolides, rabeprazole Decreased CNI levels: Barbiturates, carbamazepine, eiconacandins phenytoin, rifampin, rifabutin, St. John’s wort, ticlopidine Azathioprine allopurinol and ACE inhibitors slow azathioprine elimination thereby causing bone marrow suppression Mycophenolate mofetil proton pump inhibitors reduce MPA peak concentrations norfloxacin & metronidazole combination reduce MPA trough concentrations rifampin reduces MPA exposure

Table 1: Common drug-drug interactions with immunosuppressants: The alteration of therapeutic drug levels or clearance of immunosuppressants