Drug Interaction Report

Fosphenytoin may significantly reduce the blood levels of sirolimus, which may make the medication less effective in treating your condition. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Grapefruit and grapefruit juice may interact with sirolimus and could lead to potentially dangerous effects. Avoid eating grapefruit or drinking grapefruit juice while you are taking sirolimus. Also, you should preferably take sirolimus at least one hour before eating. If you do take it with food, you should take it each time with food to avoid changes in sirolimus levels. The oral liquid form of sirolimus must be mixed with water or orange juice only. Do not use grapefruit juice to mix this medication.