The effect of isosorbide-5-mononitrate (5-ISMN) Durules(R) on exercise tolerance in patients with exertional angina pectoris. A placebo controlled study

Twenty-four patients with stable exercise-induced angina pectorisentered a double-blind cross-over study. Isosorbide-5-mononitrate(5-ISMN) 60 mg in a controlled release formulation (Durules^®)given once daily was compared with identical placebo. The exercisetolerance was determined by bicycle ergometry before and 3 hafter a single dose of 5-ISMN and following one week's treatmentwith 5-ISMN and placebo. Nineteen patients completed the study.Exercise tolerance until the onset of chest pain and until 1mm ST segment depression increased significantly 3 h after dose.The same increase was seen both after a single dose and thesame dose under steady-state conditions. No increase was seenwith placebo. The heart rate and systolic blood pressure reactionsin the standing position were less pronounced 3 h after dosein steady-state than after a single dose of 5-ISMN. Headachewas the only bothersome side-effect reported. The study demonstratesthat 60 mg 5-ISMN in a Durules^® formulation given once dailyhas a significant anti-anginal effect and that tolerance doesnot develop.