MILRINONE

Fetal Risk Summary

Milrinone is used IV in the treatment of congestive heart disease. Reproductive studies in rats (doses up to 40 mg/kg/day) and rabbits (doses up to 12 mg/kg/day) have revealed an increased resorption rate, but no teratogenic effects (1). No reports describing the use of this drug in human pregnancy have been located.

In an experiment with four pregnant baboons at 155–165 days' gestation (term 175 days), milrinone was given as an IV bolus of 75 µg/kg followed by a continuous infusion of 1 µg/kg/minute for 180 minutes (loading and maintenance doses considered to be maximal in humans) (2). Placental transfer was demonstrated as early as 5 minutes after beginning. At steady state (60 minutes), the maternal:fetal concentration ratio was 4:1. Although a significant increase in maternal heart rate was measured during the experiment, no significant changes were observed in the maternal mean arterial pressure or in the fetal heart rate and arterial blood gasses or pH values. All four fetuses appeared normal at birth.

Breast Feeding Summary

No data are available.

References

1. Product information. Primacor. Sanofi Pharmaceuticals, 2000.
2. Atkinson BD, Fishburne JI Jr, Hales KA, Levy GH, Rayburn WF. Placental transfer of milrinone in the nonhuman primate (baboon). Am J Obstet Gynecol 1996;174:895–6.