Although sustained-release nitrates have been introduced in capsule form in an attempt to achieve prolonged therapeutic action, no objective data are available regarding the efficacy of such preparations in patients with angina pectoris. Therefore, the authors performed a double-blind investigation to study the effects of therapy with capsules of isosorbide dinitrate upon the exercise tolerance at two and six hours after administration in 28 patients with ischemic heart disease. Maximal graded multistage treadmill exercise was performed before and at two or six hours following the last dose of isosorbide dinitrate administered orally as 40-mg capsules every eight hours for one month. Isosorbide dinitrate administered in this fashion resulted in a significant reduction in anginal episodes, as compared with placebo. As compared to control, ten patients who underwent exercise testing two hours after therapy with isosorbide dinitrate manifested significantly increased duration of exercise (311 to 386 seconds) and maximal oxygen consumption (21.5 to 24.4 ml/kg/min) (both P < 0.01). Moreover, the duration of exercise was prolonged (302 to 373 seconds) and maximal oxygen consumption increased (21.1 to 23.9 ml/kg/min) (both P < 0.01) six hours following therapy with isosorbide dinitrate, compared to control. Importantly, ST-segment depression at a period identical to the termination of exercise in the control period was reduced following therapy with isosorbide dinitrate (2.3 to 1.3 mm and 2.4 to 1.5 mm at two and six hours, respectively; both P < 0.01). No significant changes were observed at either two or six hours after administration of placebo. Thus, these data indicate the capsules of isosorbide dinitrate possess a sustained antianginal action and are capable of increasing exercise tolerance for a period of six hours following administration.
|Original language||English (US)|
|Number of pages||6|
|State||Published - 1978|
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine