A placebo controlled study of flumazenil in bronchoscopic procedures

Br J Clin Pharmacol. 1997 Jan;43(1):77-83. doi: 10.1111/j.1365-2125.1997.tb00036.x.


Methods: A double-blind, randomized, placebo controlled trial of the efficacy of flumazenil was conducted in 22 consecutive patients admitted for bronchoscopy. Sedation was induced by individually titrated amounts of intravenous diazepam (mean +/- s.d., 15.75 +/- 4.4 mg). Post bronchoscopy, patients received up to 1 mg of the benzodiazepine antagonist flumazenil (Anexate) or placebo intravenously. Clinical scores for the degree of sedation, orientation in time and space, co-operation and anterograde amnesia were used. These, together with three psychometric tests were performed twice prior to bronchoscopy and on eight occasions in the following 24 h. The psychometric tests were: Tapping Test (TT), Simple Reaction Time (SRT) and Critical Flicker Fusion (CFF) and these were carried out using the automated Multipsy test system.

Results: The level of co-operation, orientation in time and space and anterograde amnesia were similar in both groups pre-and-post procedure. However compared with the pre-bronchoscopy assessment, the maximum degree of apparent sedation was significantly less in the flumazenil group in the first 4 h. In support of this, the patients in the flumazenil group also showed a significantly greater proficiency with the TT and CFF test post bronchoscopy (P < 0.05). There was no difference in the incidence of side effects and flumazenil was well tolerated.

Conclusions: In this highly controlled setting, the use of flumazenil (Anexate) was shown to be safe and effective in aiding recovery from benzodiazepine facilitated bronchoscopy and as such provides an additional level of safety for this procedure.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Aged
  • Anti-Anxiety Agents / antagonists & inhibitors
  • Antidotes / adverse effects
  • Antidotes / pharmacology*
  • Bronchoscopy / methods*
  • Conscious Sedation*
  • Diazepam / antagonists & inhibitors
  • Double-Blind Method
  • Female
  • Flumazenil / adverse effects
  • Flumazenil / pharmacology*
  • Hemodynamics / drug effects
  • Humans
  • Injections, Intravenous
  • Male
  • Middle Aged
  • Psychomotor Performance / drug effects*


  • Anti-Anxiety Agents
  • Antidotes
  • Flumazenil
  • Diazepam