Irinotecan, branded as Camptosar, Campto, Onivyde and others, is a cancer medication used to treat colon and small cell lung cancers, alone or with other drugs. Irinotecan can be processed by the cytochrome P450 3A4 enzyme, producing both the side product glutaral, as well as a compound called NPC. the NPC can then be catalyzed by liver carboxylesterase 1 to form 7-ethyl-10-hydroxy-camptothecin, or SN-38. Alternatively, irinotecan can directly form SN-38 via catalysis by liver carboxylesterase 1. After its formation, SN-38 is converted to SN-38 glucuronide by UDP-glucuronosyltransferase 2B11. This can then be converted back to SN-38 in the lysosome by beta-glucuronidase, or can be excreted as the end product of the pathway.

Irinotecan Metabolism References