BACKGROUND: The current study uses a population modeling approach to evaluate and quantify the impact of severity of asphyxia and hypoxic-ischemic encephalopathy (HIE) on the pharmacokinetics of phenobarbital in asphyxiated newborns treated with therapeutic hypothermia. METHODS: Included newborns received phenobarbital (the TOBY trial protocol). 120 plasma samples were available from 50 newborns, median (IQR) weight 3.3 (2.8-3.5) kg and gestational age 39 (39-40) weeks. NONMEM® version 7.2 was used for the data analysis. Age, body weight, sex, concomitant medications, kidney and liver function markers, as well as severity parameters of asphyxia and HIE were tested as potential covariates of pharmacokinetics of phenobarbital. Severe asphyxia was defined as pH of arterial umbilical cord blood ≤7.1 and Apgar 5 ≤5, and severe HIE was defined as time to normalization of amplitude-integrated electroencephalography (aEEG) >24 h. RESULTS: Weight was found to be the only statistically significant covariate for the volume of distribution. At weight of 1 kg volume of distribution was 0.91 L and for every additional kg it increased in 0.91 L. Clearance was 0.00563 L/h. No covariates were statistically significant for the clearance of phenobarbital. CONCLUSIONS: Phenobarbital dose adjustments are not indicated in the studied population, irrespective of the severity of asphyxia or HIE.
- MeSH
- asfyxie novorozenců * komplikace farmakoterapie MeSH
- asfyxie komplikace farmakoterapie MeSH
- dospělí MeSH
- fenobarbital farmakokinetika terapeutické užití MeSH
- lidé MeSH
- mozková hypoxie a ischemie * terapie MeSH
- novorozenec MeSH
- terapeutická hypotermie * metody MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- novorozenec MeSH
- Publikační typ
- časopisecké články MeSH
