Clinical Pharmacology of Phenobarbital in Neonates: Effects, Metabolism and Pharmacokinetics.

Article Details

Citation

Pacifici GM

Clinical Pharmacology of Phenobarbital in Neonates: Effects, Metabolism and Pharmacokinetics.

Curr Pediatr Rev. 2016;12(1):48-54. doi: 10.2174/1573397111666151026223914.

PubMed ID
26496779 [ View in PubMed
]
Abstract

Phenobarbital is an effective and safe anticonvulsant drug introduced in clinical use in 1904. Its mechanism of action is the synaptic inhibition through an action on GABAA. The loading dose of phenobarbital is 20 mg/kg intravenously and the maintenance dose is 3 to 4 mg/kg by mouth. The serum concentration of phenobarbital is up to 40 microg/ml. Nonresponders should receive additional doses of 5 to 10 mg/kg until seizures stop. Infants with refractory seizures may have a serum concentration of phenobarbital of 100 microg/ml. Phenobarbital is metabolized in the liver by CYP2C9 with minor metabolism by CYP2C19 and CYP2E1. A quarter of the dose of phenobarbital is excreted unchanged in the urine. In adults, the half-life of phenobarbital is 100 hours and in term and preterm infants is 103 and 141 hours, respectively. The half-life of phenobarbital decreases 4.6 hours per day and it is 67 hours in infants 4 week old.

DrugBank Data that Cites this Article

Drugs
Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
PhenobarbitalCytochrome P450 2C19ProteinHumans
Unknown
Substrate
Inducer
Details
PhenobarbitalCytochrome P450 2C9ProteinHumans
Unknown
Substrate
Inducer
Details
PhenobarbitalCytochrome P450 2E1ProteinHumans
Unknown
Substrate
Inducer
Details
Drug Interactions
DrugsInteraction
Amobarbital
Chloramphenicol
The metabolism of Amobarbital can be decreased when combined with Chloramphenicol.
Amobarbital
Somatostatin
The risk or severity of adverse effects can be increased when Somatostatin is combined with Amobarbital.
Butabarbital
Chloramphenicol
The metabolism of Butabarbital can be decreased when combined with Chloramphenicol.
Butabarbital
Somatostatin
The risk or severity of adverse effects can be increased when Somatostatin is combined with Butabarbital.
Butalbital
Chloramphenicol
The metabolism of Butalbital can be decreased when combined with Chloramphenicol.