Decreased drug binding in serum from patients with chronic hepatic disease

The binding of 3 drugs to serum proteins of patients with chronic hepatic disease has been studied by an ultrafilitration technique, and compared to that of normal subjects. The binding of phenylbutazone was reduced in all patients, salicylate in patients with inactive liver disease and sulphadiazine in patients whose disease was active. Analysis of binding data showed a real reduction in the capacity of albumin to bind the drugs in the majority of patients. Addition of bilirubin to normal plasma caused a reduction in sulphadiazine binding, but had no effect on the binding of salicylate or phenylbutazone. The possible causes of this reduction in binding are discussed.