Pharmacological Profile of Ibopamine

Abstract

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 β₂ receptors and an indirect vasodilation (presynaptic DA₂ and α₂-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 β₁ and β₂ and very modestly vascular synaptic α₁ – and α₂-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 epi-nine. Epinine is the active metabolite of ibopamine and is more active than dopamine on DA₁ DA₂, α₁, α₂ and β₁ and β₂ receptors. Ibopamine can be safely associated with captopril and digoxin but not with nifedipine.