Pharmacokinetics and bioavailability of carvedilol, a vasodilating beta-blocker

The pharmacokinetics and absolute bioavailability of carvedilol have been studied in 20 male healthy volunteers in a randomised 4-period, cross-over trial. Carvedilol 12.5 mg was given i.v., 50 mg was administered p.o. as a suspension and 25 and 50 mg were given in a capsule formulation. For the 50 mg capsule Cmax was 66 micrograms.l-1, tmax 1.2 h, t1/2 6.4 h. The t1/2 after i.v. administration was 2.4 h, CL 589 ml/min and VZ 132 l. The absolute bioavailability was 24% (50 mg capsule). The kinetics after the 25 and 50 mg capsules were consistent with dose linearity.