Is premedication with oral glycopyrrolate as effective as oral atropine in attenuating cardiovascular depression in infants receiving halothane for induction of anesthesia?

The authors conducted a double-blind study to compare premedication with oral glycopyrrolate and oral atropine in prevention of bradycardia and hypotension during induction of anesthesia with halothane-N2O in 90 outpatient infants and children aged 1-18 mo who were randomized into three groups to receive either an oral placebo, oral atropine (0.02 mg/kg), or oral glycopyrrolate (0.05 mg/kg) approximately 1 h before induction of anesthesia. Heart rate and mean arterial pressure were measured before drug administration, just before induction of anesthesia, and every minute until surgical stimulation occurred. Glycopyrrolate, at the dose used, was significantly less effective than atropine in attenuating bradycardia during induction; neither glycopyrrolate nor atropine altered the incidence or degree of hypotension. Antisialagogic activity and side effects were comparable, except for significantly more flushing with atropine.