Effect of cimetidine on the pharmacokinetics of the new beta-blocker betaxolol.

The effect of cimetidine on the new beta-blocker betaxolol (Kerlone) was investigated in 7 healthy volunteers. Propranolol was used as a reference beta-blocking drug. In the control study, a single oral dose of propranolol (80 mg) was given (D0) followed by 5 daily doses of cimetidine (1 g) (D1-D6) and a second oral dose of propranolol (D7). The study was repeated with 20 mg of betaxolol replacing the propranolol dose. The oral clearance of propranolol was significantly decreased (21%). No significant effect of cimetidine on the kinetics of betaxolol was observed.