Background: Phenobarbital is the most commonly prescribed anticonvulsant to control seizure in asphyxiated neonates. In spite of limited clinical evidence regarding the best use of drug, dose and duration: it appears that long term prophylactic phenobarbital might slow psychomotor development.

Objective: to assess the neuro developmental morbidity in asphyxiated neonates with long term anticonvulsant.

Material & Methods: A total of 70 asphyxiated neonates with HIE-II/ III, gestational age ≥ 35 weeks were enrolled from January 2017-january 2018 in this RCT where cases were categorized into three groups by lottery method. Group A and B received PHB 5mg/kg/day twice daily and PHB 2.5mg/kg/day once daily respectively while Group C didn’t receive any anti-seizure medication. Neurodevelopmental and electrophysiological assessment was done monthly upto 6 months of age in every cases. Data were analyzed by Chi-square & logistic regression test to find out the outcome.

Result: Mean GA was 37.74±0.98 weeks, M: F was 3:2. At 6 months 33 cases were analyzed, 11 were in each group. Cognitive impairment was found more in group A (50%) followed by group B (33.3%) and group C (16.67%) (p= 0.05). Significant motor delay was observed in Group A (42.8%) and group B (42.8%) in comparison to group C (14.28%) (p=0.04). Electrophysiological abnormality was also predominant in group A (44.4%) than group B (22.2%) and group C (11%) but not statistically significant.

Conclusion: Long term use of phenobarbital may impair psychomotor development.