Studies of drugs given before anaesthesia. XVII: anticholinergic premedicants

The effects of premedication with the anticholinergic drugs atropine, hyoscine and glycopyrronium when administered by oral and i.m. routes have been evaluated in patients undergoing minor surgery and compared with a placebo using a double-dummy double-blind technique. Although the mouths of those patients who received adequate doses of anticholinergic drugs were dry, subjectively and observed, as compared with those who received a placebo, the overall course of anaesthesia did not appear to be different. Of the three drugs atropine seemed to be absorbed best following oral administration. Equally effective oral and i.m. doses of atropine were considered to be 2.0 and 1.0 mg respectively; of hyoscine 1.0 and 0.25--0.5 mg. The appropriate dose of glycopyrronium was 0.2 mg i.m. The routine use of anticholinergic drugs in preanaesthetic medication in minor surgery appears to be unnecessary.