Clinical Pharmacological Studies with the Long-Acting β-Adrenoceptor Blocking Drug Bopindolol

Bopindolol is a potent beta-adrenoceptor antagonist with mild intrinsic sympathomimetic activity that exhibits a long duration of action. The cardiac beta-adrenoceptor blockade produced by an oral dose of 1 mg bopindolol is of similar intensity as that seen after atenolol 100 mg p.o. or pindolol 10 mg p.o. Like other beta-adrenoceptor antagonists, bopindolol is effective in inhibiting resting and stimulated plasma renin activity. In contrast to compounds lacking ISA, bopindolol does not produce undesirable changes in plasma lipoprotein composition during chronic therapy. Its bioavailability after oral administration amounts to about 70%. In the studies reviewed, bopindolol was well tolerated even after an oral dose of 12 mg, which, as far as beta-adrenoceptor blockade is concerned, would be equivalent to a single oral dose of about 1.2 g of atenolol. The onset of action of bopindolol is relatively slow, a feature that to a certain extent might account for the good tolerance of the drug observed in experimental and therapeutic studies. The delayed onset of action of the drug has facilitated the elucidation of the relationship between plasma levels and pharmacological effects during the period immediately after oral administration. Analysis of the temporal relationship between drug plasma levels and beta-adrenoceptor blockade provides evidence suggesting that the cardiac beta adrenoceptors lie outside the plasma compartment.