Pharmacokinetics and bioavailability of diacetolol, the main metabolite of acebutolol.

The pharmacokinetics and bioavailability of diacetolol, the principal metabolite of acebutolol, were studied in 6 healthy subjects. Plasma concentrations were determined following a single intravenous injection of diacetolol 100 mg and three oral doses of diacetolol 100, 400 and 800 mg, in random order. The average oral bioavailability of diacetolol was F: 0.302 +/- 0.052 (100 mg), 0.363 +/- 0.052 (400 mg) and 0.426 +/- 0.068 (800 mg); the differences are not significant. The mean plasma half-life of the terminal phase, 7.94 +/- 0.26 h after intravenous administration, was significantly higher than after oral administration 12.27 +/- 1.00 h (100 mg), 12.82 +/- 1.59 h (400 mg) and 13.05 +/- 13.05 +/- 1.22 h (800 mg) (p less than 0.02 to 0.05); the mean urine half-lives of the terminal phase were not significantly different. Renal clearance of diacetolol 10.2 +/- 0.81 . h-1 represented about wo-thirds of total body clearance 15.9 +/- 1.21 . h-1. The results suggest either a first-pass effect or incomplete absorption of diacetolol after oral administration.

RCT Entities:   Population Interventions Outcomes