Sirolimus
1 medicine
Sirolimus is an immunosuppressant used to prevent organ transplant rejection. It increases the risk of serious infections and certain cancers, and requires regular blood-level monitoring because its safe dose range is narrow.
Key facts
- Sirolimus (sold as Rapamune) is an mTOR inhibitor that suppresses the immune system so your body does not reject a transplanted organ.
- You take it once a day, consistently with or without food, and your blood level is checked regularly to keep the dose in a safe range.
- Because it suppresses your immune system, sirolimus raises your risk of serious infections and certain cancers, particularly skin cancer and lymphoma. It also slows wound healing.
- Seek urgent care for fever, chills, a wound that will not heal, or any new lump or skin change.
What sirolimus treats
Sirolimus prevents organ rejection after a kidney transplant, usually alongside other immunosuppressants such as a corticosteroid or calcineurin inhibitor. It is also used to treat lymphangioleiomyomatosis, a rare lung disease, and certain vascular tumors and skin conditions in dedicated formulations.
How sirolimus works
Sirolimus binds to a protein inside immune cells and blocks an enzyme called mTOR, which those cells need to receive the growth signals that drive them to multiply and attack a transplanted organ. By blocking this pathway, sirolimus dampens the immune response responsible for organ rejection, while other parts of the immune system continue to function.
Before you take it
- Tell your prescriber about any history of liver disease, high cholesterol, or slow wound healing, since sirolimus can worsen all three.
- Avoid live vaccines while taking sirolimus, since your suppressed immune response may not protect you and the vaccine itself may pose a risk.
- Grapefruit juice, certain antifungal medicines, and some antibiotics can raise sirolimus blood levels; tell your prescriber about everything else you take.
- Surgical wounds heal more slowly on sirolimus, so tell any surgeon or dentist that you take it before a procedure.
Side effects
Common effects include mouth sores, high cholesterol or triglycerides, low blood counts, and swelling in the legs.
Stop and seek urgent medical care for any of these:
- Fever, chills, or any sign of a serious infection.
- Shortness of breath or a persistent new cough, which can indicate lung inflammation.
- A wound that is not healing, unusual bleeding, or bruising.
Safety essentials
- Sirolimus suppresses your immune system, raising the risk of serious infections and certain cancers, especially skin cancer. Use sun protection and attend recommended cancer screenings.
- It has a narrow gap between an effective dose and a toxic one, so regular blood tests to measure your sirolimus level are mandatory, along with cholesterol and kidney function checks.
- Tell any doctor, dentist or surgeon that you take sirolimus before a procedure, since wound healing is slower on this medicine.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.