Pharmacology · Class
mTOR inhibitors !
Drugs that block mTOR, a master switch of cell growth: used to prevent transplant rejection and to treat some cancers and rare lung and tumour diseases.
Updated 2026-11-01
What they are
Rapamycin (sirolimus) and its derivative everolimus. Sirolimus prevents kidney transplant rejection and treats lymphangioleiomyomatosis; everolimus is used in transplantation and in cancers such as advanced breast cancer, kidney cancer and neuroendocrine tumours.
Mechanism of action
Like tacrolimus, these drugs bind FKBP12 inside the cell, but the complex does not touch calcineurin. Instead it binds and inhibits mTOR, a kinase that links growth-factor and cytokine signals (such as IL-2) to cell-cycle progression and protein synthesis. T cells and tumour cells stall before entering the S phase.
Target: mTOR kinase (mTORC1), reached through FKBP12
Drugs in this class
- SirolimusA transplant drug (rapamycin) that blocks the mTOR growth switch in T cells. It raises cholesterol, slows wound…mTOR (mechanistic target of rapamycin), through FKBP12
- EverolimusAn oral mTOR inhibitor related to rapamycin, used for some breast, kidney and neuroendocrine cancers. Mouth sores…mTOR (mechanistic target of rapamycin), through FKBP12
Others in the class
- temsirolimus
Test yourself
Think of the answer, then tap the question to see it.
Sirolimus and tacrolimus both bind FKBP12. How do their targets differ?
The tacrolimus-FKBP12 complex inhibits calcineurin; the sirolimus-FKBP12 complex leaves calcineurin alone and inhibits mTOR.
Why is sirolimus often delayed or avoided right after surgery in some transplant recipients?
It impairs wound healing and causes lymphocele and wound dehiscence.
Which laboratory abnormality is especially common with mTOR inhibitors?
High cholesterol and triglycerides.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - SIROLIMUS solution (DailyMed (U.S. National Library of Medicine), 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 39 (McGraw Hill, 2023).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.