Sublingual isosorbide dinitrate therapy versus sublingual acebo in angina pectoris.

A double-blind crossover study comparing the effects of 5 mg of isosorbide dinitrate given sublingually four times daily for 4 weeks to those of a placebo also administered sublingually four times daily for 4 weeks was performed on 20 male patients with classical exeitional angina pectoris due to coronary artery disease. Isosorbide dinitrate, compared to placebo, significantly reduced the number of anginal episodes requiring nitroglycerin in only one of 17 patients (6%), did not significantly improve exercise tolerance in any of 17 patients, and did not improve the resting or exercise electrocardiograms in any of 17 patients. Isosorbide dinitrate produced headaches in 12 of 19 patients (63%), and two of these patients (11%) were unable to tolerate the drug. Isosorbide dinitrate administered sublingually is