Absorption and disposition of ibuprofen in hemodialyzed uremic patients.

The absorption and disposition of ibuprofen was investigated in seven hemodialyzed uremic patients. Ibuprofen (400 mg) was orally administered to each patient 1 hr or 4 hr prior to hemodialysis. Uremic patients appeared to absorb ibuprofen at a slower rate as compared to normal subjects. The hemodialysis systems used in this study yielded a mean extraction efficiency of 16.7% for ibuprofen, with a mean dialysis plasma clearance of 22.7 ml/min. The drug recovery resulting from hemodialysis represented a small fraction of the ingested dose of ibuprofen (less than 4%). The half-life of ibuprofen (1.3-1.9 hr) was not significantly altered by hemodialysis. Observations of extraction efficiency, drug recovery and half-life during dialysis suggested nondialyzability of ibuprofen, probably due to its extensive protein binding (approximately 90%). Uremic patients may require a comparatively longer time to achieve the therapeutic concentration attained in normal volunteers. However, dosage adjustment is not required once a regimen is implemented in uremia.