Docetaxel Renal Excretion
No, docetaxel is not renally excreted and does not require dose adjustment for impaired renal function in patients with metastatic breast cancer. 1
Primary Route of Elimination
Docetaxel undergoes predominantly hepatobiliary elimination, with approximately 75% of the administered radioactivity excreted in feces within 7 days and only 6% excreted in urine. 1
About 80% of the radioactivity recovered in feces is excreted during the first 48 hours as metabolites, with less than 8% as unchanged drug. 1
The drug is metabolized by the CYP3A4 isoenzyme in the liver before excretion. 1
Clinical Implications for Renal Impairment
Poor renal function is listed as a patient risk factor for developing febrile neutropenia during docetaxel treatment, but this relates to overall patient vulnerability rather than altered drug clearance. 2
Population pharmacokinetic analyses have not identified renal function as a significant factor influencing docetaxel clearance or requiring dose modification. 1
The mean total body clearance of docetaxel is 18 L/h/m² with a terminal elimination half-life of 116 hours, neither of which is significantly affected by renal function. 1
Dose Adjustment Considerations
Dose adjustments for docetaxel are required for hepatic impairment, not renal impairment. 1, 3
In patients with mild to moderate liver impairment (AST/ALT >1.5 times ULN with alkaline phosphatase >2.5 times ULN), total body clearance is lowered by 27%, resulting in a 38% increase in systemic exposure. 1
Docetaxel is not recommended for patients with liver metastases or impaired liver function because clearance is impaired through the hepatobiliary route. 3
Patients with combined abnormalities of transaminase and alkaline phosphatase should not be treated with docetaxel. 1
Important Caveat
- While renal excretion is minimal, patients with poor renal function may still be at higher risk for treatment-related complications such as febrile neutropenia due to their overall compromised physiological state, requiring closer monitoring and supportive care with G-CSF when appropriate. 2