Milrinone

Chemical

Selective PDE III inhibitor → pipyridine derivative

Use

Cardiac failure (acute)

Dose

Load: 50mcg/kg over 15 mins

Infusion: 0.5mcg/kg/min

Presentation

10mg/10ml ampoules, clear and colourless

Route

IV/PO

Onset

5 – 15 mins

DoA

t ½ 3 hrs

MoA

Competitive inhibition PDE III

  • ↓hydrolysis of cAMP ∴↑cAMP of myocardium & smooth m.

Β1 Receptor of Heart = ↑Ca++

+ inotropy

+ chronotropy

+ dromotropy

Β2 Receptor of Heart = ↑Ca++

+ inotropy

Β2 Receptor of Smooth m.

Inhibits MLCK

↓

Smooth m. relaxation

PD

CVS

  • +ve inotropy
  • Vasodilation
  • Minimal effect on HR & myocardial O2 consumption

PK

A

OBA 92% (IV only in Hus)

D

PPB 80%

VD 0.4L/kg

M

10% hepatically metabolized

E

Renally excreted

80% unchanged → renal dose adjustment

Adverse Effects

↓SVR