Determination of the anti-ischemic activity of nebivolol in comparison with atenolol.

The anti-ischemic effect of 5 mg nebivolol o.i.d., a newly developed beta 1-selective adrenoceptor blocking drug with vasodilating properties, was compared with that of atenolol (100 mg o.i.d.) following a treatment period of 6 days. The study was performed in 24 patients with documented coronary artery disease and stable angina pectoris according to a double-blind randomized study, designed using conventional symptom-limited exercise testing. Exercise testing 3 h after the first dose showed a more marked ST-segment reduction by atenolol than by nebivolol (59% vs. 18%). ST-segment depression measured 24 h after administration 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). Approximately 3 h after the last dose, the reduction was comparable (45% and 38% by nebivolol and atenolol, respectively). Exercise duration, exercise time necessary to produce ST-segment depression by 0.1 mV and exercise time to the onset of angina were also prolonged following administration of both drugs. Thus, at steady-state single daily doses of 100 mg atenolol and 5 mg nebivolol were about equieffective when measured at time of maximal effect (i.e. 3 h after drug administration). However, duration of action with respect to the ST-segment depression seems to be slightly longer for nebivolol.