5-fluorouracil systemic exposure (5-FU AUC)

5-fluorouracil systemic exposure is a pharmacokinetic parameter, typically quantified as the Area Under the Curve (AUC), representing the total drug concentration in a patient's plasma over a specific timeframe (PubMed: 29159882). It is not a biological target such as a receptor or enzyme, but rather a clinical measurement used in therapeutic drug monitoring (TDM) to optimize chemotherapy dosing (StatPearls: NBK482392). The drug 5-fluorouracil (5-FU) is an antimetabolite that targets thymidylate synthase (TYMS), an enzyme crucial for DNA synthesis (UniProt: P04818). Because 5-FU has a narrow therapeutic index and its metabolism is highly variable—largely due to the activity of the dihydropyrimidine dehydrogenase (DPD) enzyme—monitoring systemic exposure is essential to prevent severe toxicities like neutropenia and mucositis while ensuring sufficient anti-tumor activity (PubMed: 25108247). Consequently, 5-fluorouracil systemic exposure serves as a critical surrogate for both safety and efficacy in oncology treatment regimens (PubMed: 18445839). Optimizing this exposure through dose adjustment has been shown to improve clinical outcomes and reduce the incidence of adverse events compared to body surface area-based dosing (PubMed: 25108247).

Other names

5-FU AUC5-FU plasma exposure5-fluorouracil Area Under the Curve5-FU systemic levels

5-fluorouracil systemic exposure is a measure of drug availability; the drug 5-fluorouracil acts by inhibiting thymidylate synthase (TYMS) and incorporating into RNA and DNA to induce cell death (StatPearls: NBK482392).