Comparison of some postanaesthetic effects of atropine and glycopyrrolate with particular emphasis on urinary problems.

Two hundred and two patients undergoing elective surgery were given either atropine (98 patients) or glycopyrrolate (104 patients) for intravenous premedication and as an adjunct to reversal of neuromuscular block by neostigmine in a double-blind study. The dose ratio of atropine and glycopyrrolate was 2.5:1. After reversal, both drugs induced an initial increase and a subsequent decrease in heart rate. The mean values in % heart rate were statistically significantly higher in the glycopyrrolate group than in the atropine group. Semiquantitative measurement of salivation showed glycopyrrolate to be more potent as an antisialogogue drug. Nausea and vomiting were equally common after both drugs. There were no differences between the drugs in the occurrence of postoperative micturition difficulties, the total rate of this complication being 18%. It is concluded that factors other than the choice of anticholinergic drug may be blamed for postoperative micturition difficulties.