Milrinone(Win 47203) is a PDE3 inhibitor that increases intracellular cyclic adenosine monophosphate resulting in improved ventricular function and vasodilation.
IC50 Value: 2 mM( inhibiting human platelet aggregation)
Target: PDE3
in vitro: Milrinone inhibited PDE4 in addition to PDE3 activity. In isolated rabbit cardiomyocytes, milrinone (>10 microM) caused greater elevations in intracellular cAMP and calcium than cilostazol. cilostazol and milrinone were equally effective in inhibiting human platelet aggregation with a median inhibitory concentration (IC50) of 0.9 and 2 microM, respectively. In rabbit ventricular myocytes, however, cilostazol elevated cAMP levels to a significantly lesser extent (p < 0.05 vs. milrinone)
in vivo: Increased blood concentrations of milrinone were associated with increased inhibition of ADP and AA-induced platelet activation (P < 0.0001). Milrinone at a blood concentration of 300 ng/mL markedly impaired the platelet activation response to ADP and AA.  Treatment with milrinone led to improvement in biventricular myocardial function [mean right ventricular index from 0.521 (SD-0.213) to 0.385 (SD-0.215), p = 0.003; mean left ventricular index from 0.636 (SD-0.209) to 0.5 (SD-0.171), p = 0.012). No difference was found in the values of heart rate corrected right or left ventricular ejection time prior to and while on treatment with milrinone (right ventricle: mean, 1.23 (SD-0.42) and 1.14 (SD-0.48), p = 0.29; left ventricles: mean, 1.17 (SD-0.51) and 1.13 (SD-0.48), p = 0.66).
Clinical trial: Inhaled Milrinone in Cardiac Surgery. Phase2

PDE
Mirodenafil
Nortadalafil
Oglemilast
Olprinone
PDE-9 inhibitor
Pentoxifylline
PF-04447943
PF-2545920
Pimobendan
Roflumilast