Failure of ketanserin, a serotonin inhibitor, to prevent spontaneous or ergonovine-induced attacks of variant angina

Six patients hospitalized with active variant angina were treated for 3 days with the serotonin antagonist ketanserin after a 3 day control period on no medication. The number of variant angina episodes per patient per day was 1.52 ± 1.42 during the control period and 2.05 ± 2.30 during ketanserin therapy (p = NS). Ergonovine was administered in incremental doses of 0.0125 mg to 0.4 mg in the control period, during intravenous ketanserin administration and after 3 days of oral treatment. All 6 patients developed ST elevation during all 3 ergonovine tests. The ergonovine dose at which ST elevation developed was similar in each of the 3 periods. It is concluded that ketanserin is of no value in the treatment of variant angina and that both spontaneous and ergonovine-induced spasm in man are unlikely to be mediated by a serotonergic mechanism.