The use of dobutamine in myocardial infarction for reversal of the cardiodepressive effect of metoprolol.

1 Ten patients with acute myocardial infarction were infused dobutamine in increasing doses up to 15 microgram kg--1 min--1. 2 Metoprolol (total dose 15 mg) was then given intravenously to nine of these patients and the beta-adrenoceptor against effects produced by dobutamine were effectively reversed. 3 Nine patients with acute myocardial infarction pretreated with metoprolol (15 mg) were infused dobutamine 15 microgram kg--1 min--1 for 10 min. This resulted in effective reversal of the beta-adrenoceptor antagonist effects induced by metoprolol, without the occurrence of serious arrhythmias or other unwanted effects. 4 Dobutamine may be valuable in counteracting any undesirable cardiodepressive effects of beta-adrenergic receptor blocking drugs (especially the cardioselective agents) in patients with acute myocardial infarction.