SN38pitoisuudet

SN38pitoisuudet refers to the concentrations of SN38, the active metabolite of irinotecan, in the body. Irinotecan is a chemotherapy drug used to treat various cancers, particularly colorectal cancer. After administration, irinotecan is converted in the liver by the enzyme carboxylesterase 2 (CES2) into SN38. SN38 is significantly more potent than irinotecan as an inhibitor of topoisomerase I, an enzyme crucial for DNA replication and repair.

The concentration of SN38 in the plasma and at the tumor site is a key determinant of both the efficacy and toxicity of irinotecan therapy. Higher SN38pitoisuudet are generally associated with better anti-tumor activity, as more active drug reaches the cancer cells. However, elevated SN38 levels can also lead to dose-limiting toxicities, such as severe diarrhea and neutropenia, due to SN38's cytotoxic effects on rapidly dividing cells in the gastrointestinal tract and bone marrow.

Factors influencing SN38pitoisuudet include genetic variations in genes involved in irinotecan metabolism, such as CES2 and UGT1A1 (which further inactivates SN38), as well as liver function and drug interactions. Monitoring SN38pitoisuudet, though not routinely done in clinical practice, has been investigated as a way to personalize irinotecan dosing, aiming to optimize therapeutic benefit while minimizing adverse events. Research continues to explore the clinical utility of measuring these concentrations.