DETERMINATION OF THE ANTIISCHEMIC ACTIVITY OF NEBIVOLOL IN COMPARISONWITH ATENOLOL

The anti-ischemic effect of 5 mg nebivolol o.i.d., a newly developed b eta1-selective adrenoceptor blocking drug with vasodilating properties , was compared with that of atenolol (100 mg o.i.d.) following a treat ment period of 6 days. The study was performed in 24 patients with doc umented coronary artery disease and stable angina pectoris according t o a double-blind randomized study, designed using conventional symptom -limited exercise testing. Exercise testing 3 h after the first dose s howed a more marked ST-segment reduction by atenolol than by nebivolol (59% vs. 18%). ST-segment depression measured 24 h after administrati on of the penultimate dose was statistically significantly reduced by nebivolol (from 0.19 +/- 0.07 to 0.13 +/- 0.07 mV; P = 0.0059) but not by atenolol (from 0.17 +/- 0.06 to 0.14 +/- 0.10 mV; P = 0.0703). App roximately 3 h after the last dose, the reduction was comparable (45% and 38% by nebivolol and atenolol, respectively). Exercise duration, e xercise time necessary to produce ST-segment depression by 0.1 mV and exercise time to the onset of angina were also prolonged following adm inistration of both drugs. Thus, at steady-state single daily doses of 100 mg atenolol and 5 mg nebivolol were about equieffective when meas ured at time of maximal effect (i.e. 3 h after drug administration). H owever, duration of action with respect to the ST-segment depression s eems to be slightly longer for nebivolol.