Glycopyrrolate as a substitute for atropine in neostigmine reversal of muscle relaxant drugs

A controlled study was undertaken in man to evaluate glycopyrrolate as a substitute for atropine in anaesthesia by determining the relative ability of the two drugs to protect against the cholinergic challenge provided by neostigmine administered at the conclusion of anaesthesia for reversal of neuromuscular blockade. Results indicate that glycopyrrolate offers the same protection against neostigmine-induced bradycardia as atropine with a marked reduction in the magnitude of the initial tachycardia. The dose of glycopyrrolate required to do this is 0.2 mg for each 1 mg of neostigmine administered, which is half the dose of atropine required for the same purpose.