Plasma protein binding of clonazepam in hepatic and renal insufficiency and after hemodialysis.

The plasma protein binding of clonazepam was investigated in healthy volunteers, cirrhotic patients, chronic uremic patients maintained on hemodialysis, and patients with reduced renal function. Each group consisted of six subjects. The unbound fraction of clonazepam (mean +/- SEM) was 13.9 +/- 0.2% in volunteers. 17.1 +/- 1.0% in cirrhotic patients, 1.56 +/- 0.5% before and 12.2 +/- 0.4% after hemodialysis in chronic uremic patients, and 16.0 +/- 0.7% in patients with poor renal function. The figure for the healthy subjects was significantly different from that of cirrhotic patients only. Binding of clonazepam to albumin and alpha 1-acid glycoprotein was also studied. Clonazepam bound preferentially to albumin.