Phenobarbital dosage and blood level for control of neonatal seizure

Twenty-five neonates were observed for the relationship between phenobrbital loading dose, plasma concentrations and control of seizures. Nineteen neonates (76%) had seizures controlled by phenobarbital alone. Effective plasma concentration were 10.0~31.1microgram/ml. Although 14 neonates had seizures controlled by phenobarbital concentration below 20microgram/ml, neonate required level above 30microgram/ml. We found that continued benefit was obtained until phenobarbital plasma concentrations reached 40microgram/ml and there was no adverse effects on cardiorespiratory function. We recommend that plasma phenobarbital concentrations should equal or surpass 40microgram/ml before additional anticonvulsants are used for neonates with seizure.