sulindac-sulfide and Kidney-Failure--Chronic

Sulindac was administered as a single 300-mg oral dose to six patients with end-stage renal failure and six normal subjects. Plasma concentrations of sulindac and its sulfide and sulfone metabolites were examined over a 48-hour period. As determined by ultrafiltration methods at 37 degrees C, the percentage free of sulindac and sulindac sulfide in plasma was greater, respectively, in the patients with renal failure (10.50 +/- 2.42 and 9.96 +/- 1.21) than in the normal subjects (6.78 +/- 0.45 and 6.01 +/- 0.37). Free sulindac plasma concentrations were not different between the two groups. However, sulindac sulfide, total and free, plasma concentrations were substantially decreased in the group with renal failure. Total area under the curve (AUC) of the sulfide metabolite was 18% in the normal subjects and the free AUC was 29%. In patients with renal failure, the apparent half-lives of sulindac (1.98 +/- 0.76 hours) and sulindac sulfide (15.6 +/- 5.8 hours) were not different from those of normal subjects. Sulindac sulfone half-life was highly variable and longer in the patient group. Studies of dialysis clearance showed that sulindac and its metabolites are poorly dialyzed. A 4-hour dialysis period increased the plasma binding of both sulindac and sulindac sulfide in the patient group. Based on the decreased plasma concentration of the active sulindac sulfide metabolite in the patient group, dosage adjustments may be required in patients with end-stage renal failure.

Topics: Administration, Oral; Adult; Anti-Inflammatory Agents, Non-Steroidal; Female; Half-Life; Humans; Kidney Failure, Chronic; Male; Metabolic Clearance Rate; Middle Aged; Protein Binding; Renal Dialysis; Sulindac

In normal humans sulindac, a prodrug, undergoes two major biotransformations: irreversible oxidation to the inactive sulfone metabolite and reversible reduction to the pharmacologically active sulfide metabolite. To assess any effect of end-stage renal failure on sulindac biotransformation, six patients were given 200 mg sulindac orally. Plasma was sampled over 24 hours. Protein binding of sulindac and metabolites was determined by equilibrium dialysis. Results were compared with historic controls. AUC(0-12) for sulindac and the sulfone were similar to controls. AUC(0-12) for the sulfide was significantly reduced to 4.85 micrograms X hr/ml from 13.1 micrograms X hr/ml (P less than 0.02). Protein binding of all three compounds was significantly reduced by renal failure. When corrected for protein binding, the AUC(0-12) for sulindac and the sulfone was twice that of controls whereas that of the sulfide was 42 ng X hr/ml compared with 83 ng X hr/ml in normal individuals (P less than 0.001). This suggests that end-stage renal failure impairs the reduction of sulindac to the active sulfide whereas oxidation to the sulfone is intact.

Topics: Administration, Oral; Adult; Biological Availability; Biotransformation; Chromatography, High Pressure Liquid; Female; Humans; Indenes; Kidney Failure, Chronic; Kinetics; Male; Middle Aged; Sulindac