NCIt definition : A cardiovascular bipyridine agent and phosphodiesterase (PDE) III inhibitor, with
positive inotropic and vasodilator activities. Upon administration, milrinone selectively
inhibits PDE-mediated degradation of cyclic adenosine monophosphate (cAMP) in the
heart and vascular muscles, thereby increasing cAMP and activates protein kinase A
(PKA). This leads to phosphorylation of calcium ion channels and improve myocardium
contractile force. Milrinone also causes vasodilation in arteriolar and venous vascular
smooth muscle.;
Alternative definition : ACC/AHA: Milrinone is a phosphodiesterase 3 inhibitor that works to increase the heart's
contractility, decrease pulmonary vascular resistance, and as a systemic vasodilator.;