EFFECT OF ORAL DIAZEPAM ON THE SENSITIVITY OF UPPER AIRWAY REFLEXES

In a double-blind, cross-over study, we have investigated theeffect of oral diazepam 20 mg and placebo on the sensitivityof upper airway reflexes in 10 male volunteers (aged 25–35yr). Upper airway reflex sensitivity (UARS) was assessed usingsmall concentrations of ammonia vapour as a stimulus to upperairway receptors. A threshold concentration of ammonia, at whichreflex glottic closure occurred in response to the ammonia stimulus,was used as a measure of UARS. With diazepam, there was significantdepression of UARS from 30 to 150 min after administration.(Br. J. Anaesth. 1993; 70: 131–134)