These immunosuppressive drugs include methotrexate, cyclophosphamide, cyclosporine or azathioprine. Calcineurin inhibitors such as cyclosporine, tacrolimus, diazoxide, and minoxidil can cause hyperkalemia. Another cause is neurotoxicity due to exposure to certain drugs such as tacrolimus and cyclosporine. Erythromycin, ketoconazole and cyclosporine are CYP3A4 inhibitors and therefore inhibit the metabolic pathway of docetaxel. Oral medications may include hydroxychloroquine, doxycycline, mycophenolate mofetil, cyclosporine, or corticosteroids. Immunosuppressants used for CU include cyclosporine, tacrolimus, sirolimus, and mycophenolate. Standard prophylaxis involves the use of cyclosporine for six months with methotrexate. It inhibits the metabolism of theophylline, caffeine, cyclosporine and warfarin. Development of an immunosuppressant drug, cyclosporine A, made transplants a more viable option for patients. Other alternatives to corticosteroid treatment include dapsone, doxycycline, clofazimine, and cyclosporine. Most commonly used treatments include high-dose glucocorticoids, and cyclosporine. Verapamil and cyclosporine A are common inhibitors for MDR 1. The risk of toxicity to the kidneys increases when ketorolac is taken with cyclosporine. Elevated serum levels of cyclosporine have been reported with concomitant use of cyclosporine with norfloxacin. In multiple clinical trials, vitamin E lowered blood concentration of the immuno-suppressant drug, cyclosporine A.