Measuring blood sirolimus (rapamycin) concentration is used to monitor drug levels during treatment, monitor patient compliance, and assess drug toxicity.
Sirolimus (Rapamune®) is a medication in the mTOR inhibitor class. It was originally discovered as a natural product produced by the bacterium Streptomyces hygroscopicus.
Sirolimus is primarily used as an immunosuppressant. It was initially approved to prevent organ rejection in kidney transplant patients. It is also used in some cases to prevent rejection in liver and heart transplant patients.
The primary mechanism of action of sirolimus is its ability to inhibit the activity of the mammalian target of rapamycin (mTOR). This protein kinase regulates various cellular processes, including cell growth, proliferation, and survival. By blocking mTOR, sirolimus interferes with the signaling pathways involved in immune response, reducing the immune system's ability to attack and reject transplanted organs.
Besides its immunosuppressive properties, sirolimus has also shown promise in other medical applications. It has been used to treat certain types of cancer, such as renal cell carcinoma (a type of kidney cancer) and subependymal giant cell astrocytoma (a brain tumor). Sirolimus has also been investigated for its potential benefits in treating various autoimmune diseases, including rheumatoid arthritis and systemic lupus erythematosus.
Some common side effects include mouth ulcers, diarrhea, high cholesterol levels, high blood pressure, and an increased risk of infections. Sirolimus may also affect kidney function and can cause an increase in blood sugar levels.