Prednisolone protein binding in renal transplant patients.
Prednisolone pharmacokinetics and protein binding characteristics were studied in 10 renal transplant patients with various degrees of renal function (serum creatinine: 80-380 mumol/l) who received their usual oral maintenance dose of prednisolone (0.18 +/- 0.04 mg/kg). Plasma was assayed for prednisolone and hydrocortisone by h.p.l.c. and free prednisolone concentrations were determined in each sample by a rapid ultrafiltration technique. Free prednisolone area under curve (AUCu) ranged from 101 to 436 ng ml-1 h and was 6.3 to 15.0% of total prednisolone AUC. The fraction AUCu/AUC was closely related to serum albumin and creatinine concentrations determined at the time of study (multilinear regression correlation coefficient r2 = 0.830, P less than 0.0001); elevated serum creatinine and low albumin concentrations were associated with a higher % free. These results suggest that much of the variability in prednisolone protein binding could be attributed to inter-patient variability in serum albumin and creatinine concentrations. Total prednisolone concentrations would be potentially misleading in any comparisons made between patient groups with different renal function.
D000328:Adult; D001798:Blood Proteins / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011239:Prednisolone / Q000008:administration & dosage / Q000097:blood*; D011485:Protein Binding; D012709:Serum Albumin / Q000032:analysis; D014462:Ultrafiltration
D001798:Blood Proteins; D012709:Serum Albumin; D011239:Prednisolone; D003404:Creatinine; D006854:Hydrocortisone