Exercise tolerance in angina is improved by mivazerol--an alpha 2-adrenoceptor agonist

In a double-blind, placebo-controlled, randomized trial of treadmill exercise tolerance in six patients with chronic stable angina, intravenous mivazerol 1 microgram, 2 micrograms, and 3 micrograms/kg increased the time to onset of angina by 39%, 48%, and 76%; the time to 1-mm ST depression by 36%, 76%, and 104%; and total exercise duration by 15%, 23%, and 30%, respectively. In a subsequent double-blind, placebo-controlled, randomized trial involving a further 12 patients, a single oral dose of mivazerol of 800 micrograms, 1200 micrograms, and 1600 micrograms increased the time to onset of angina by 4%, 11%, and 30%; the time to 1-mm ST depression by 33%, 43%, and 53%; and the total exercise duration by 10%, 18%, and 23%, respectively. Mivazerol is an imidazole derivative with agonist properties at the alpha 2-adrenoceptor and appears to be an effective antianginal. Mivazerol may improve exercise performance by attenuating the effects of exercise-induced sympathetic nervous system activity on the ischemic myocardium.