title: Cimetidine induces coronary artery spasm in patients with vasospastic angina.
abstract: We have previously reported that cimetidine, a histamine H2-receptor blocker, augments the histamine-induced coronary vasoconstriction at the site of spastic segments in the atherosclerotic coronary arteries of swine. To elucidate whether cimetidine has a coronary vasoconstrictive effect in humans, 14 patients with vasospastic angina (group 1) and 14 controls with atypical chest pain (group 2) were examined angiographically. Nitroglycerin-effective spontaneous angina with electrocardiographic ST-T changes and ergonovine-induced coronary artery spasm were confirmed in group 1, but not in group 2. Cimetidine was administered intravenously in a dose of 200 mg. Cimetidine induced coronary artery spasm in 4 patients in group 1 but none in group 2(29% vs. 0%, p less than 0.01). The extent of coronary vasoconstriction induced by cimetidine was greater at the site of spastic coronary segments than that at the site of non-spastic segments in group 1 or all segments in group 2 [14% vs. 4%, (p less than 0.01) or 14% vs. 2%, (p less than 0.01)] as well as the extent of ergonovine-induced coronary vasoconstriction [46% vs. 14%, (p less than 0.01) or 46% vs. 14%, (p less than 0.01)] and nitroglycerin-induced coronary vasodilatation [58% vs. 25%, (p less than 0.01) or 58% vs. 17%, (p less than 0.01)]. As it was suggested that cimetidine has potential vasoconstrictive effects in patients with coronary artery spasm, it should be administered with caution in patients with the vasospastic angina pectoris.
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002927:Cimetidine / Q000009:adverse effects* / Q000097:blood; D003329:Coronary Vasospasm / Q000139:chemically induced*; D004874:Ergonovine / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D002927:Cimetidine; D004874:Ergonovine