Pharmacological profile of ibopamine. A summary of experiments on anaesthesized dogs

This review summarizes the results obtained with ibopamine on anaesthesized dogs. Ibopamine is a dopamine-related drug active by oral route, namely the diisobutyric ester of N-methyl-dopamine. Ibopamine is able to activate dopamine specific and adrenergic receptors in the heart and circulation, inducing a vasodilating activity together with a mild positive inotropic effect without increasing heart rate and myocardial O2 consumption. The activation of dopamine and adrenergic receptors mediates a direct vasodilation postjunctional DA1 and beta 2 receptors and an indirect vasodilation (presynaptic DA2 and alpha 2-receptors) through the inhibition of the release in norepinephrine, the renin-angiotensin system, and the secretion of aldosterone and vasopressin, thus antagonizing the neurohormonal alterations in congestive heart failure through a receptor mechanism. Ibopamine can also activate beta 1- and beta 2 and very modestly vascular synaptic alpha 1- and alpha 2-receptors, thus inducing a mild positive inotropic activity and avoiding a drop in arterial pressure which might take place in presence of the intense vasodilation induced by the drug. There is some difference in potency between dopamine and epinine. Epinine is the active metabolite of ibopamine and is more active than dopamine on DA1, DA2, alpha 1, alpha 2 and beta 1 and beta 2 receptors. Ibopamine can be safely associated with captopril and digoxin but not with nifedipine.