Comparison of acute haemodynamic effects of dopexamine hydrochloride, dobutamine and sodium nitroprusside in chronic heart failure

Dopexamine hydrochloride (Dopacard®) is a new synthetic catecholamine compound, which possesses potent β2-adrenergic and D A 1-dopaminergic agonistic properties. It is free of a-adrenergic activity, has no β1-adrenergic activity and is less potent at D A2-dopaminergic receptors than dopamine. In the present study the acute haemodynamic effects of dopexamine hydrochloride were compared to those of dobutamine and nitroprusside in 12 patients with idiopathic congestive cardiomyopathy in an open crossover study. With dopexamine hydrochloride, there were dose-dependent increases from control in cardiac output and stroke volume, decreases in blood pressure, right and left atrial pressure, systemic vascular resistance and pulmonary vascular resistance and little change in heart rate. Similar effects were seen with nitroprusside, apart from a marked increase in heart rate, and with dobutamine, except that systolic aortic blood pressure increased and there was no change in diastolic or mean pressure or pulmonary artery systolic pressure. In general, dopexamine hydrochloride produced effects between those produced by the other two treatments. This suggests that dopexamine with its combined vasodilator and inotropic action has a desirable cardiovascular profile with advantages over the β1-receptor aganist dobutamine and the pure vasodilator sodium nitroprusside.