Induction of the metabolism of etizolam by carbamazepine in humans

Eur J Clin Pharmacol. 2005 May;61(3):185-8. doi: 10.1007/s00228-005-0904-y. Epub 2005 Mar 18.


Objective: To examine the effect of carbamazepine on the single oral dose pharmacokinetics of etizolam.

Methods: Eleven healthy male volunteers received carbamazepine 200 mg/day or placebo for 6 days in a double-blind, randomized, crossover manner, and on the sixth day they received a single oral 1-mg dose of etizolam. Blood samplings and evaluation of psychomotor function by the Digit Symbol Substitution Test and Stanford Sleepiness Scale were conducted up to 24 h after etizolam dosing. Plasma concentration of etizolam was measured using high-performance liquid chromatography.

Results: Carbamazepine treatment significantly decreased the peak plasma concentration (17.5+/-4.1 ng/ml versus 13.9+/-4.1 ng/ml; P<0.05), total area under the plasma concentration-time curve (194.8+/-88.9 ng h/ml versus 105.9+/-33.0 ng h/ml; P<0.001), and elimination half-life (11.1+/-4.6 h versus 6.8+/-2.8 h; P<0.01) of etizolam. No significant change was induced by carbamazepine in the two pharmacodynamic parameters.

Conclusions: The present study suggests that carbamazepine induces the metabolism of etizolam.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Analgesics, Non-Narcotic / pharmacology
  • Area Under Curve
  • Carbamazepine / pharmacology*
  • Chromatography, High Pressure Liquid
  • Cross-Over Studies
  • Diazepam / administration & dosage
  • Diazepam / analogs & derivatives*
  • Diazepam / blood
  • Diazepam / pharmacokinetics
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Drug Interactions
  • Half-Life
  • Humans
  • Male
  • Metabolic Clearance Rate / drug effects
  • Tranquilizing Agents / administration & dosage
  • Tranquilizing Agents / metabolism
  • Tranquilizing Agents / pharmacokinetics


  • Analgesics, Non-Narcotic
  • Tranquilizing Agents
  • Carbamazepine
  • etizolam
  • Diazepam