The effect of a clinically effective and non-effective dose of lorazepam on 7.5% CO(2) -induced anxiety

Alison Diaper, Andreas Papadopoulos, Ann S Rich, Gerry R Dawson, Colin T Dourish, David J Nutt, Jayne E Bailey

Research output: Contribution to journalArticle (Academic Journal)peer-review

9 Citations (Scopus)


Symptoms of anxiety induced by 7.5% CO(2) inhalation can be attenuated by acute administration of GABA(A) receptor anxiolytics such as lorazepam and alprazolam. This study investigated if these effects are dose-related, by comparing a 0.5 mg dose (considered non-clinically effective) and a 2 mg dose of lorazepam (clinically effective) on 7.5% CO(2) inhalation. Eighteen healthy males (mean age 20.6 years, SD 1.29), judged physically and mentally fit, attended three visits, each one week apart, to take each treatment in a randomised double-blind crossover design. Drugs were given 60 min prior to 20 min air inhalation, followed by 20 min 7.5% CO(2) inhalation. The order of gas presentation was single blind. Subjective ratings using visual analogue scales (VAS) and questionnaires were recorded before and after each inhalation. Blood pressure (BP), heart rate (HR), respiration rate (RR) and expired CO(2) were recorded during each inhalation. Inhalation of 7.5% CO(2) significantly raised BP, HR, RR and expired CO(2) . Ratings of feeling like leaving the room were significantly lower on 2 mg compared with 0.5 mg and placebo, and dose-dependent trends were seen in scores for VAS fearful, anxious, stressed, tense, and worried. Results may be indicative of dose-dependent effects of lorazepam in a CO(2) model of anxiety. Copyright © 2012 John Wiley & Sons, Ltd.
Original languageEnglish
JournalHuman Psychopharmacology
Issue number6
Early online date2 Oct 2012
Publication statusPublished - Nov 2012


Dive into the research topics of 'The effect of a clinically effective and non-effective dose of lorazepam on 7.5% CO(2) -induced anxiety'. Together they form a unique fingerprint.

Cite this