A selective phospodiesterase 3 inhibitor known to effect left ventricular relaxation by inhibiting the breakdown of cAMP in association with an acceleration of sarcoplasmic reticulum Ca(2)-ATP activity and CA(2) uptake. It inhibits platelet aggregation and induces disaggregation.

Milrinone is an inhibitor of type 3 phosphodiesterases (PDEs), inhibiting recombinant PDE3A and PDE3B with IC50 values of 0.45 and 1 µM, respectively. It is selective for PDE3 over PDE1, PDE2, PDE4, PDE5, and PDE7 (IC50s = 263, >300, 17.5, 49.1, and 58.3 µM, respectively). Milrinone (0.1-1 mg/kg) has positive...