European Journal of Clinical Pharmacology

, Volume 23, Issue 1, pp 87–92 | Cite as

Kinetics of phenobarbital in normal subjects and epileptic patients

  • A. J. Wilensky
  • P. N. Friel
  • R. H. Levy
  • C. P. Comfort
  • S. P. Kaluzny


The kinetics of phenobarbital (PB) were evaluated in six normal subjects and six epileptic patients treated with phenytoin or carbamazepine. Each normal subject received three single doses of PB: PB-sodium 130 mg i.v. (IV), PB sodium 130 mg i.m. (IM), and PB acid 100 mg orally (PO), in random order at least one month apart. After IV PB distributive half-lives varied from 0.13 to 0.70 h, disposition half-lives were 75 to 126 h, steady state volume of distribution (Vss) was 0.54±0.03 l/kg, and clearance (CL) was 3.8±0.77 ml/h/kg. Absolute bioavailability of IM PB was 101±13%, of PO PB (corrected for dose) 100±11%. Peak serum PB concentrations were achieved from 2 to 8 h after IM administration, and from 0.5 to 4 h after PO administration. Epileptic patients exhibited similar PB kinetics: disposition half-lives were 77 to 128 h, Vss 0.61±0.05 l/kg, and Cl 3.9±0.76 ml/h/kg. Phenobarbital appears to represent an exception among antiepileptic drugs, in that pharmacokinetic data obtained in normals can reasonably be extrapolated to the epileptic population.

Key words

phenobarbital epilepsy kinetics bioavailability epileptic patients 


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Copyright information

© Springer-Verlag 1982

Authors and Affiliations

  • A. J. Wilensky
    • 1
  • P. N. Friel
    • 1
  • R. H. Levy
    • 1
    • 2
  • C. P. Comfort
    • 1
  • S. P. Kaluzny
    • 1
  1. 1.Regional Epilepsy Center, Department of Neurological Surgery, School of MedicineUniversity of WashingtonSeattleUSA
  2. 2.Department of Pharmaceutics, School of PharmacyUniversity of WashingtonSeattleUSA

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