Comparative effects of hyoscine butylbromide and atropine sulphate on sleep architecture in healthy human volunteers.

The changes in sleep architecture, heart rate and respiratory rate to hyoscine butylbromide (HBB), a peripherally acting anticholinergic was studied. These effects were compared with that of atropine sulphate, a drug known to cross the blood brain barrier. The study followed a single blind cross over design with a one week washout period. Atropine sulphate (0.4 mg) and HBB (10 mg) were given intravenously to ten adult healthy male volunteers before sleep onset. Normal saline was used as control. All night sleep polysomnography was done with the standard montage for sleep staging. Respiration and airflow were also monitored. Rapid eye movement (REM) latency was significantly increased with both the drugs whereas the duration of REM sleep was decreased only with atropine. Slow wave sleep (SWS) was also increased significantly by atropine. There was no change in heart rate, or respiratory rate during any of the sleep stages. HBB affects the initiation of REM sleep whereas atropine affects both its initiation and maintenance.