Evaluation of oxprenolol slow release and osmotic release by exercise testing and ambulatory electrocardiographic monitoring in patients with chronic stable angina pectoris
We have treated eleven patients with chronic stable angina pectoris with slow-release oxprenolol (160 mg and 320 mg) in a double-blind crossover study and evaluated its efficacy objectively by exercise testing between 180 and 240 min after dosing. The mean exercise time increased significantly from 6.2 min on placebo to 7.2 min and 7.3 min on oxprenolol 160 mg and 320 mg respectively. No overall beneficial effects could be demonstrated for the higher dose. A further 20 patients received slow release oxprenolol 160 mg and 10/170 mg “Oros” (osmotic release) oxprenolol in a double-blind crossover study using exercise testing and ambulatory electrocardiographic monitoring at 21–23 h after dosing. The mean exercise time increased significantly from 7.0 min on placebo to 8.3 min on slow-release oxprenolol and to 8.1 min on “Oros” oxprenolol. The effects of the 2 treatments on exercise and ambulatory heart rates were comparable. Two patients were withdrawn during the doubleblind treatment period while receiving oxprenolol slow-release, one because of unstable angina and another becaues of throbbing headache. These findings confirm that slow-release oxprenolol is effective in treating chronic stable angina pectoris at the 160-mg dose. “Oros” oxprenolol 10/170 mg has a profile of action closely similar to but without any additional benefit over slow-release oxprenolol 160 mg.