|Gd-sirolimus||Tablet||5 mg||Oral||Genmed A Division Of Pfizer Canada Inc|
|Gd-sirolimus||Solution||1.0 mg||Oral||Genmed A Division Of Pfizer Canada Inc|
|Gd-sirolimus||Tablet||2 mg||Oral||Genmed A Division Of Pfizer Canada Inc|
|Gd-sirolimus||Tablet||1.0 mg||Oral||Genmed A Division Of Pfizer Canada Inc|
|Rapamune||Tablet, coated||2 mg||Oral||Pfizer|
|Rapamune||Tablet, sugar coated||1 mg/1||Oral||Wyeth Pharmaceuticals Inc., a subsidiary of Pfizer Inc.|
|Rapamune||Tablet, sugar coated||1 mg/1||Oral||Cardinal Health|
|Rapamune||Tablet, coated||0.5 mg||Oral||Pfizer|
|Rapamune||Tablet, coated||1 mg||Oral||Pfizer|
A macrolide compound obtained from Streptomyces hygroscopicus that acts by selectively blocking the transcriptional activation of cytokines thereby inhibiting cytokine production. It is bioactive only when bound to immunophilins. Sirolimus is a potent immunosuppressant and possesses both antifungal and antineoplastic properties.
Sirolimus inhibits T lymphocyte activation and proliferation that occurs in response to antigenic and cytokine (Interleukin IL-2, IL-4, and IL-15) stimulation by a mechanism that is distinct from that of other immunosuppressants. Sirolimus also inhibits antibody production. In cells, sirolimus binds to the immunophilin, FK Binding Protein-12 (FKBP-12), to generate an immunosuppressive complex. The sirolimus:FKBP-12 complex has no effect on calcineurin activity. This complex binds to and inhibits the activation of the mammalian Target Of Rapamycin (mTOR), a key regulatory kinase. This inhibition suppresses cytokine-driven T-cell proliferation, inhibiting the progression from the G1 to the S phase of the cell cycle.