Clinical Evaluation of Sublingual Nitrates

Abstract

A preliminary study was set up to compare onset of action and duration of 2 sublingual nitrates, nitroglycerin and isosorbide dinitrate. Forty-five patients were interviewed for their subjective impressions. Nitro-glycerin was judged to have a more rapid onset of action. Isosorbide dinitrate was judged to have a more sustained duration of action. Twenty patients selected for objective studies were exercised, and electrocardiographic changes were continuously monitored during and after exercise on the RKG-100. Immediate action of nitroglycerin was slightly more rapid than that of isosorbide dinitrate. Duration of action of isosorbide dinitrate was more marked than that of nitroglycerin, as shown during exercise 30 minutes after drug administration. This sustained protection remained at a high level for 1 and 2 hours after isosorbide dinitrate, but was decreased markedly 1 hour after nitroglycerin administration.