Protein Binding of Drugs in Plasma from Patients with Acute Renal Failure

: It was found by in vitro experiments that the protein binding of acetylsalicylic acid, salicylic acid, phenylbutazone, diphenylhydantoin, sulphadiazine and thiopental was decreased in the plasma of 10 surgical patients with acute renal failure. The plasma was taken 4 to 8 days after the onset of the renal failure. At a drug concentration of 400 μg/ml the decreases ranged from 21.8 to 60.3 % as compared with a normal control group. At drug concentrations in or near the normal therapeutic level, the protein binding was even more decreased for the salicylic acids and sulphadiazine but less decreased for diphenylhydantoin and thiopental. The decreased binding could only partly be explained by the lower concentration of albumin in the patients: 3.0 g/100 ml ± 0.48 (S.D.) compared to 4.1 g/100 ml ± 0.53 (S.D.) (P < 0.01).