Klinische Wochenschrift

, Volume 64, Issue 23, pp 1217–1221

Influence of propranolol coadministration or cigarette smoking on the kinetics of desmethyldiazepam following intravenous clorazepate

  • H. R. Ochs
  • D. J. Greenblatt
  • A. Locniskar
  • J. Weinbrenner
Originalien

DOI: 10.1007/BF01734459

Cite this article as:
Ochs, H.R., Greenblatt, D.J., Locniskar, A. et al. Klin Wochenschr (1986) 64: 1217. doi:10.1007/BF01734459

Summary

The influence of propranolol coadministration or of cigarette smoking on the kinetics of desmethyldiazepam following a single 20-mg intravenous dose of clorazepate dipotassium was evaluated in healthy volunteers. In Study One, intravenous clorazepate was given once in the control condition, and again during coadministration of propranolol, 80 mg twice daily. Compliance with the prescribed propranolol regimen was verified by measurement of serum propranolol concentrations (mean, 37 ng/ml). In control vs propranolol treatment conditions, there was no significant difference in desmethyldiazepam volume of distribution (1.27 vs 1.23 liters/kg) or in free fraction in serum (1.83 vs 1.80% unbound). There was a small although statistically significant prolongation of desmethyldiazepam half-life (55 vs 61 h,P<0.05) and reduction in clearance (0.281 vs 0.247 ml/min/kg,P<0.02) attributable to propranolol. In Study Two, desmethyldiazepam kinetics were compared in eight cigarette smokers (mean, 19 cigarettes/day) and in 11 nonsmoking controls matched for age, sex, and body weight. There was no significant difference between controls and cigarette smokers in desmethyldiazepam volume of distribution (1.29 vs 1.34 liters/kg), elimination half-life (55 vs 59 h), clearance (0.284 vs 0.276 ml/min/kg), or free fraction in serum (1.96 vs 1.92% unbound). Thus, propranolol slightly although significantly impairs the clearance of desmethyldiazepam and prolongs its halflife. Cigarette smoking has no apparent influence on desmethyldiazepam kinetics.

Key words

PharmacokineticsDesmethyldiazepamClorazepatePropranololSmoking

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • H. R. Ochs
    • 1
    • 2
  • D. J. Greenblatt
    • 1
    • 2
  • A. Locniskar
    • 1
    • 2
  • J. Weinbrenner
    • 1
    • 2
  1. 1.Marienkrankenhaus Soest, Medizinische UniversitätsklinikUniversität BonnBundesrepublik Deutschland
  2. 2.Division of Clinical Pharmacology, Departments of Psychiatry and MedicineTufts University School of Medicine and New England Medical Center HospitalBoston