The effects of lorazepam on skin conductance responses to aversive stimuli in healthy subjects.
BACKGROUND
Autonomic responses to aversive stimuli are widely used to model anxiolytic drug effects in healthy humans. Benzodiazepine anxiolytics dose dependently attenuate autonomic responses to aversive stimuli by their anxiolytic as well as sedative action. The present study aimed to examine the effects of non-sedative doses of lorazepam on skin cutaneous responses to aversive stimuli and subjective mood.


METHODS
A randomized, double blind, cross over study of 12 healthy male volunteers aged 24 years (23-32; median; range) was carried out. Subjects received single oral doses of 0.5 and 1.0 mg lorazepam as well as placebo on three different occasions with at least 5 days in-between. Skin conductance responses (SCRs) to unpleasant pictures and noises, pupillary unrest index as well as subjective levels of anxiety were measured repeatedly before and after drug administration.


RESULTS
SCRs were found significantly lower 2 hours following ingestion of 0.5 mg lorazepam as well as 1, 2 and 3 hours after 1.0 mg lorazepam were given as compared to baseline conditions. By contrast, administration of placebo did not influence SCRs to a significant extent. Both doses of lorazepam did not change pupillary unrest index nor subjective mood.


CONCLUSIONS
Lorazepam may attenuate SCRs to aversive stimuli without affecting vigilance nor subjective mood. Attenuation of autonomic responses to aversive stimuli may not be specific for an anxiolytic effect.
Siepmann
Martin
M
Institute of Clinical Pharmacology, Medical Faculty, Technical University, 01307, Dresden, Germany. martin.siepmann@tu-dresden.de
Heine
Benjamin
B
Kluge
Andreas
A
Ziemssen
Tjalf
T
Mück-Weymann
Michael
M
Kirch
Wilhelm
W
D000161:Acoustic Stimulation; D000328:Adult; D000339:Affect / Q000187:drug effects / Q000502:physiology; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D001007:Anxiety / Q000523:psychology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004644:Emotions / Q000187:drug effects* / Q000502:physiology; D005712:Galvanic Skin Response / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008140:Lorazepam / Q000494:pharmacology*; D008297:Male; D010775:Photic Stimulation; D012025:Reflex, Pupillary / Q000187:drug effects
D014151:Anti-Anxiety Agents; D008140:Lorazepam