See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include: aluminum/magnesium antacid, cyclosporine, sirolimus, temsirolimus, ziprasidone, other drugs that may increase the level of potassium in the blood (such as "water pills" including amiloride, spironolactone), other drugs that weaken the immune system/increase the risk of infection (such as natalizumab, rituximab).

Avoid alcohol when using this medication because it may cause the medication to be released too quickly and increase the risk of side effects.

Other medications can affect the removal of tacrolimus from your body, which may affect how tacrolimus works. Examples include azole antifungals (such as itraconazole, voriconazole), cimetidine, danazol, ethinyl estradiol, methylprednisolone, nefazodone, HIV protease inhibitors (such as nelfinavir), rifamycins (such as rifampin, rifabutin), ritonavir, St. John's wort, certain anti-seizure drugs (such as phenobarbital, phenytoin), among others.