There is potential for complications with all posttransplant medication regimens, including both from immunosuppression medications as well as other routine prophylactic medications including aspirin, ganciclovir, trimethoprim sulfamethoxazole, and ranitidine ( Table 125.4 ) The two main classifications of immunosuppressant medications used are CNIs (cyclosporine and tacrolimus) and the purine antagonists or antimetabolites (azathioprine and mycophenolate mofetil) The typical immunosuppressant medications used in liver transplantation include corticosteroids, CNIs, and antimetabolites Similarly, heart transplant recipients receive maintenance immunosuppression with a CNI and a purine antagonist; most programs have moved away from chronic steroid use Long-term use of immunosuppression medications has been associated with an increased risk for renal insufficiency, hypertension, diabetes, hyperlipidemia, lymphoproliferative disease/lymphoma, increased infection risk, obesity, and metabolic syndrome TABLE 125.4 ADVERSE EFFECTS OF IMMUNOSUPPRESSIVE AGENTS a Corticosteroids are used in both the initial immunosuppression setting as well as for the treatment of acute cellular rejection Corticosteroid therapy decreases