Cardiac adverse effects of early dexamethasone treatment in preterm infants: A randomized clinical trial

This study evaluates the effects of early administration of dexamethasone o n left ventricle dimensions and their clinical significance in preterm infa nts. Fifty preterm infants with birth weight less than or equal to 1250 g a nd gestational age less than or equal to 30 weeks were randomly assigned af ter 72 hours of life to the dexamethasone group (n = 25) or to the control group (n = 25). The treated infants received dexamethasone intravenously fr om the 4th day of life for 7 days (0.5 mg/kg/day for the first 3 days, 0.25 mg/kg/day for the next 3 days, and 0.125 mg/kg/day for the 7th day). Seria l echocardiographic measurements of end systolic interventricular septum th ickness, end diastolic interventricular septum thickness, end systolic left ventricle posterior wall thickness, end diastolic left ventricle posterior wall thickness, left ventricle end diastolic diameter, and left ventricle end systolic diameter were taken before starting dexamethasone, on days 3 a nd 7 of treatment, 7 days after the interruption of treatment, and at the 2 8th day of life. Five infants of each group were excluded by the final anal ysis because of the lack of a complete cardiac evaluation, leaving 20 treat ed and 20 control infants. Infants receiving dexamethasone had a significan tly larger increase in mean septal and left posterior wall thickness during the treatment and 7 days after the dexamethasone weaning. The mean left ve ntricle diameter of treated infants was significantly lower than that of co ntrol infants from the 7th day of treatment to the 28th day of life. Four n eonates (20%) in the dexamethasone group developed left ventricular myocard ial hypertrophy without left ventricle outflow tract obstruction, showing s igns of decreased cardiac output and ischemic changes on ECG. The daily flu id intake was increased to 200 ml/kg to ensure an adequate preload volume, and the complete resolution of left ventricle hypertrophy was obtained with in the 2nd to 3rd week after dexamethasone weaning. Preterm infants receivi ng an early (< 96 hours of life) short course of dexamethasone develop a le t ventricular myocardial hypertrophy that can be symptomatic and clinically significant. Preterm infants included in future studies with the goal to f ind the minimum dose and duration of dexamethasone treatment should be stri ctly monitored echocardiographically for this side effect. (C) 2001 the Ame rican College of Clinical Pharmacology.