indication

Indicated for the treatment of congestive heart failure.

pharmacology

Milrinone, a synthetic dimethylxanthine derivative structurally related to theophylline and caffeine, is used in the treatment of peripheral vascular diseases and in the management of cerebrovascular insufficiency, sickle cell disease, and diabetic neuropathy.

mechanism of action

Milrinone inhibits erythrocyte phosphodiesterase, resulting in an increase in erythrocyte cAMP activity. Subsequently, the erythrocyte membrane becomes more resistant to deformity. Along with erythrocyte activity, Milrinone also decreases blood viscosity by reducing plasma fibrinogen concentrations and increasing fibrinolytic activity.

toxicity

LD₅₀ = 0.3 mg/L in rats

biotransformation

There are five metabolites but the O-glucuronide represents the major pathway of biotransformation.

absorption

Milrinone is rapidly and almost completely absorbed after oral administration. Bioavailability is 92% (in healthy volunteers).

half life

2.3 hours

route of elimination

The primary route of excretion of milrinone in man is via the urine.