Plasma half‐life of phenylbutazone in patients with impaired liver function

Abstract

In 6 patients with cirrhosis at the liver and 5 control patients, the serum concentrations of phenylbutazone (pbz) and a major metabolite, oxphenylbutazone (ox‐pbz), were followed for 16 days after oral administration of fixed doses of pbz for 4 days (600, 600,300,300 mg). Preliminary evidence is presented for a significant correlation between the apparent elimination rate constant of pbz (the plasma half‐life) and the galactose elimination capacity (r = 0.868, P < 0.05) in cirrhotic patients. The ratio between the peak concentrations at pbz and ox‐pbz in the two groups was not different.