Newer inotropes in pediatric heart failure.

In the cardiac setting in pediatrics, inotropic support is often employed based on the extrapolation from adult studies, the underlying pathophysiology, pharmacodynamics of inotropes, and anecdotal experience. Large pediatric critical care studies involving inotropic support are rare. Levosimendan, a calcium-sensitizing agent with inotropic and lusitropic properties, is a pyridazole dinitrate derivative with linear pharmacokinetics and a relatively short half life, although an active metabolite, namely, OR-1876, has a half life of 70-80 hours accounting for a prolonged effect. Albeit few, pediatric studies involving levosimendan suggest similar pharmacokinetics to adults with heart failure, an efficacy at least equal to that of milrinone, favorable myocardial oxygen effects, and an ability to decrease concomitant catecholamine dosing. Levosimendan may be a promising new agent in pediatrics, but further experience and study are warranted. Finally, istaroxime, a calcium cycling agent that is in the beginning of adult study, may be another inotrope with lusitropic properties that might be applicable to pediatric patients.