The influence of hemodialysis on the pharmacokinetics of ibuprofen and its major metabolites.

The pharmacokinetics of ibuprofen and its two major metabolites, the hydroxy and carboxy derivatives, were studied in seven functionally anephric subjects undergoing hemodialysis therapy. Subjects received ibuprofen 800 mg tid for 14 days. Hemodialysis was performed three times weekly during this period. Arterial and venous blood samples were collected before dialysis and along with dialysate, and during the final dosing interval and dialysis session. No accumulation of ibuprofen plasma concentrations and an absence of intact ibuprofen in dialysate indicated clearance through metabolic pathways. The metabolites did accumulate significantly (mean plasma levels, carboxy 249 micrograms/mL and hydroxy 57 mu/mL); however, both were detected in dialysate. Mean extraction efficiencies were 0.16 (hydroxy) and 0.15 (carboxy). Dialysis clearance calculated by arterial-venous difference was found to agree with actual recovery in dialysate for both metabolites. Side effects were not observed in any subject.