Increased Plasma Protein Binding of Propranolol and Chlorpromazine Mediated by Disease-Induced Elevations of Plasma α1Acid Glycoprotein

Abstract

To assess the importance of disease-induced increases in plasma concentrations of α₁ acid glycoprotein (an acute-phase plasma protein that binds cationic drugs), we determined binding of propranolol in plasma from 53 patients and 25 healthy volunteers. Binding was increased in 10 patients with Crohn's disease (P0.80). Chlorpromazine binding, determined in 60 subjects, yielded similar results. Percentage of free drug and α₁ acid glycoprotein concentration were inversely correlated (r = -0.77 with propranolol, P1 acid glycoprotein concentration, which may influence drug kinetics. (N Engl J Med 299:1435–1439, 1978)