Cyclosporine and Tacrolimus Toxicities Cyclosporine (Neoral®) and Tacrolimus (Prograf®, FK506) belong to a class of drugs called calcineurin inhibitors. They block the action of immune cells in the blood which normally detect and attack your transplanted organ leading to rejection. These medications may have side effects that are unpleasant and can cause other medical problems. Many medications, including over-the counter and herbal medications, may unfavorably interact with cyclosporine and tacrolimus, increasing your risk of drug toxicities. Monitoring of drug levels regularly and taking all prescribed medications as directed can lower the risk of side effects. In some instances, other medications may be required to treat the side effects from cyclosporine or tacrolimus. For example, a decrease in magnesium level and an increase in potassium level in the blood may occur requiring treatment. Also, some transplant patients develop high blood pressure with the use of these drugs which may be treated with calcium-channel blockers (e.g. Norvasc®). Both cyclosporine and less commonly tacrolimus may elevate blood sugar. Dry mouth, increased thirst, or increased urination may be signs of diabetes. For patients who develop diabetes, oral medications that lower blood sugar may be required, but insulin may be necessary in some extreme instances. Lipid levels may be raised by these drugs. A class of medications called "statins" (e.g. Lipitor®, Pravachol®) can be used to lower lipid levels without unfavorably interacting with anti-rejection drugs.
