Effect of temazepam on tracheobronchial mucus clearance.

BACKGROUND Tracheobronchial clearance of mucus from the lungs is reduced during sleep and, usually, by the administration of opiates. It seemed possible therefore that temazepam, a widely used potent benzodiazepine, retarded clearance. METHODS The effect of 10 mg temazepam on mucociliary clearance was studied in eight healthy volunteers, aged 18-50 (mean 30) years, in a randomised, placebo controlled, double blind, cross-over study. Six subjects were female and two male. Six were non-smokers and two were light current smokers. Clearance was assessed from the change in radio-activity in the lungs after inhalation of 5 microns diameter polystyrene particles, labelled with technetium-99m, under controlled conditions. RESULTS Tracheobronchial clearance was reduced by 22% after temazepam by comparison with placebo during the first three hours after drug ingestion; this is the period when circulating drug concentrations are highest. CONCLUSION Temazepam should be prescribed with caution in patients with impaired lung mucociliary transport.