Neostigmine is the anticholinesterase drug most commonly used to reverse blockade or speed up recovery from neuromuscular blockade from nondepolarizing neuromuscular blocking drugs. Because of its cardiac muscarinic effects, prior or simultaneous administration of glycopyrrolate or atropine is usually recommended. There have been a few case reports of bradycardia, atrio-ventricular (AV) block, and cardiac arrest following neostigmine/glycopyrrolate administration to reverse neuromuscular block affecting several patients.

In this report, we describe a case of 21-year-old with a history of seizure disorder and developmental delay that presented for dental surgery under general anesthesia and developed type I AV block following the simultaneous administration of neostigmine and glycopyrrolate to reverse a nondepolarizing neuromuscular block with rocuronium at the end of his surgery.

We suggest that the chronic use of antiepileptic drugs in this patient in combination with neostigmine and glycopyrrolate lead to AV block in this patient. We also review similar cases reported in the literature and suggest an explanation for this observed phenomenon.