A randomized, triple-blind, placebo-controlled trial of prophylactic oral phenobarbital to reduce the need for phototherapy in G6PD-deficient neonates.

OBJECTIVE: Decreased conjugation is probably more important than hemolysis for causing jaundice in G6PD-deficient neonates. The role of enzyme inducers, like phenobarbital, in G6PD deficiency is unclear. This randomized controlled trial was performed to evaluate Phenobarbital's role in reducing the need for phototherapy among G6PD-deficient neonates.

STUDY DESIGN: This stratified, randomized, triple-blinded, placebo-controlled trial was conducted in a level III NICU. Consecutive babies with gestation >/=34 weeks and birth weight >/=1800 g were screened from cord blood. G6PD-deficient neonates, who were otherwise healthy, were enrolled. Rh isoimmunization, maternal Phenobarbital use and lack of parental consent were exclusion criteria. Subjects were randomly allocated to receive 5 mg/kg day of oral phenobarbital/ placebo for first 3 days. They were monitored daily for total serum bilirubin (TSB) until declining TSB was documented twice. The primary outcome was requirement for phototherapy and secondary outcomes were duration of phototherapy, need for exchange transfusion, peak TSB and adverse effects. Sample size of 56 could detect a decline in phototherapy requirement from 40 to 5% with 80% power and 5% error.

RESULTS: Of 2370 babies screened, 63 were G6PD-deficient. Of them, 56 eligible babies were allocated to phenobarbital (n=27) or placebo (n=29). The mean age of administration of the first dose was 18.55+/-7.3 h. In total, 44% in phenobarbital group and 41% in placebo group required phototherapy (p=1.0). There was no significant difference in exchange transfusion rates (18.5 vs 10%, p=0.46). No baby had adverse reactions.

CONCLUSION: Prophylactic oral phenobarbital does not decrease the need for phototherapy or exchange transfusions in G6PD-deficient neonates.