Potentiated renal dysfunction w/ aminoglycosides, vancomycin, co-trimoxazole, ciprofloxacin, melphalan, amphotericin B, ketoconazole, NSAIDs (eg, azapropazone, diclofenac, naproxen, sulindac), cimetidine, ranitidine, fibric acid derivatives (eg, fenofibrate, bezafibrate), MTX, colchicine, tacrolimus. Increased conc w/ colchicine. Increased risk of lymphoma & other neoplasm w/ immunosuppressive & antineoplastic agents. Increased blood sirolimus conc. Elevated MTX AUC in patients w/ RA. Concomitant use w/ K-sparing drugs (eg, ACE inhibitors, angiotensin II receptor antagonists) & K-containing drugs & K-rich diet. Altered plasma & blood conc w/ drugs or foods affecting hepatic microsomal enzymes eg, cytochrome P450 subfamily CYP3A. Decreased metabolism & increased conc w/ diltiazem, nicardipine, verapamil, mibefradil, fluconazole, itraconazole, ketoconazole, voriconazole, clarithromycin, erythromycin, quinupristin/dalfopristin, methylprednisolone, allopurinol, amiodarone, bromocriptine, colchicine, imatinib, danazol, OCs, metoclopramide. Increased metabolism & decreased conc w/ nafcillin, rifampin, carbamazepine, oxcarbazepine, phenobarb, phenytoin, octreotide, sulfinpyrazone, terbinafine, ticlopidine. Decreased plasma clearance of prednisolone. Increased plasma conc w/ methylprednisolone. Increased bioavailability w/ grapefruit juice. Diminished immune response to live vaccines. Increased AUC & absorption w/ metoclopramide. Decreased absorption w/ orlistat. Decreased plasma conc w/ bosentan. Decreased vol of distribution & serum clearance of digoxin.