measurement of blood phenobarbital concentration in newborns admitted to the nicu of imam reza hospital and receiving the drug via intravenous mode

Introduction: newborns may be treated with phenobarbital for many reasons. because in each region, depending on different races and genetic factors, different pharmacokinetic conditions govern the drug. it is essential to control blood levels of certain drugs, especially phenobarbital, and maintain these levels during treatment. in this study, we measure the level of phenobarbital in newborns who receive intravenous.methods: in this study, venous blood was collected from 50 neonates who received intravenous phenobarbital at a loading dose of 20 mg/kg weight, and at least, three days had passed since the maintenance dose of 5 mg/kg body weight in 24 hours, and sent to the laboratory. phenobarbital blood levels were measured, and the results were analyzed descriptively.results: in this study, the average weight of newborns in two groups was 9.93 ± 2.58 kg. the mean blood concentration of phenobarbital, three days after starting the maintenance dose in the group of infants weighing more than 2.5 kg was 3.33 ± 9.1 micrograms/liter, in the group of infants weighing less than 2 kg. and half a kilogram or lbw was 5.9 ± 9.5 micrograms/liter, and in the group weighing less than 1.5 kg vlbw was 14.4 ± 15.46 micrograms/liter. there was no significant difference between case and control group (p>0.05). three days after starting the maintenance dose in all three groups, the mean blood phenobarbital concentration was 9.86 ± 0.86 micrograms/liter.conclusion: blood phenobarbital levels in our newborns are below therapeutic levels at day two, so phenobarbital levels should be evaluated.