Neostigmine
Bloxiverz
Acetylcholinesterase inhibitor
Reversibly inhibits AChE → ↑ACh at NMJ → outcompetes non-depolarizing relaxants. Co-administer antimuscarinic (glycopyrrolate or atropine) to block muscarinic side effects.
Indications
- •NDMR reversal
- •Myasthenia gravis maintenance
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| NMB reversal | 0.04–0.07 mg/kg IV (max 5 mg) + glycopyrrolate 0.2 mg per 1 mg neo | 0.05–0.07 mg/kg IV |
Pharmacokinetics
Onset 5–10 min. Duration 60 min. Renal + hepatic clearance.
Hemodynamic effects
Bradycardia, ↓BP if antimuscarinic not given.
Side effects
- !Bradycardia, asystole
- !Bronchoconstriction, ↑secretions
- !↑GI motility (problematic for fresh anastomoses?)
- !PONV
Contraindications
- ×Mechanical bowel/urinary obstruction
- ×Asthma (relative)
Clinical pearls
- ★Don't reverse 0 twitches — give time or use sugammadex.
- ★Maximum reversal at TOF count ≥ 2; ratio ≥ 0.9 needed for safe extubation.
- ★Glyco preferred over atropine — matches neostigmine onset and avoids tachycardia.
Other drugs in Anticholinesterases
- Pyridostigmine
Reversibly inhibits acetylcholinesterase → ↑acetylcholine at the neuromuscular junction. Quaternary ammonium → does NOT cross BBB → no CNS effects. Longer-acting than neostigmine; mainstay of chronic myasthenia gravis treatment.
- Edrophonium
Reversible AChE inhibitor with the FASTEST onset (1–2 min) and SHORTEST duration (5–10 min) of the anticholinesterases. Quaternary structure → no CNS penetration. Largely historical; replaced by sugammadex in NMB reversal and by serologic AChR antibody testing in myasthenia diagnosis.
- Physostigmine
Reversible AChE inhibitor with TERTIARY amine structure → CROSSES blood-brain barrier (unlike neostigmine, pyridostigmine, edrophonium). The only AChE inhibitor that treats CENTRAL anticholinergic syndrome.
Browse all classes: /reference/drugs
Suggested reading
- •Stoelting & Hines, Pharmacology & Physiology in Anesthetic Practice, 6e
- •Miller's Anesthesia, 9e
- •FDA package insert
