DOSAGE PROGRAMMING OF PHENOBARBITAL IN NEONATAL SEIZURES

Owing to the changes occurring in the organism as a result of biologic al maturation, disposition kinetics of phenobarbital in newborns is si gnificantly different to that observed in the paediatric and adult pop ulations. Moreover, the disposition parameters change constantly durin g the first days of life. The data on the serum levels of phenobarbita l in 17 newborns were analysed to quantify the changes in the eliminat ion half-life of phenobarbital during the first weeks of life. The hal f-life of the drug was estimated to be (mean+/-SD) 114.2+/-43.0 h, 73. 19+/-24.17 h and 41.23+/-13.95 h in patients 1-10, 11-30 and 31-70 day s old, respectively. According to these values and assuming phenobarbi tal serum levels of 20 mg/l to be safe and effective in neonatal seizu res, the initial dosing recommended is 2.9, 4.8 and 6.0 mg/kg/day in n ewborns 1-10, 11-30 and 31-70 days old, respectively.