Anaes · Neuromuscular blockade & reversal
Neostigmine reversal of neuromuscular blockade
Also known as Anticholinesterase reversal · Acetylcholinesterase inhibition · Neostigmine plus glycopyrrolate · Competitive-block reversal
Neostigmine is a reversible acetylcholinesterase inhibitor that raises the concentration of acetylcholine at the neuromuscular junction so that it outcompetes a non-depolarising blocker at the postsynaptic nicotinic receptor, restoring neuromuscular transmission (Kronauer 2026; Tao 2026). It reverses ONLY non-depolarising (competitive) blocks; it does not reverse and in fact augments a depolarising (suxamethonium phase I) block, so it must never be used to reverse sux. It must be given only once spontaneous recovery has begun — ideally at a train-of-four count of 4 with fade — because there is a ceiling effect beyond a maximum dose and a risk of neostigmine-induced weakness (a cholinergic-excess depolarising-type block) if it is overdosed. It MUST be co-administered with an anticholinergic, glycopyrrolate preferred (or atropine), to block the muscarinic effects of bradycardia, bronchospasm, salivation and gut cramps, in a ratio of roughly 5 parts neostigmine to 2 parts glycopyrrolate. Compared with sugammadex (Tsai 2026; Leslie 2026; Martins de Brito 2026; Chen 2026), neostigmine is cheap and applicable to all non-depolarisers but slower, needs evidence of recovery, has a ceiling effect, and is associated with residual blockade and postoperative pulmonary complications. It is a quaternary ammonium compound that does not cross the blood-brain barrier, and it is also used for acute colonic pseudo-obstruction (Ogilvie syndrome); off-label intrathecal use with bupivacaine for caesarean-section spinal anaesthesia has been trialled against dexmedetomidine (Zamani Kiasari 2026, n-110 elective caesarean sections, neostigmine 10 micrograms intrathecal — a spinal-adjuvant study, not a peripheral-nerve-block study).
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- Neostigmine reverses ONLY non-depolarising (competitive) blocks — it AUGMENTS a depolarising (suxamethonium phase I) block; never use it to reverse suxamethonium.
- Neostigmine MUST be co-administered with an anticholinergic (glycopyrrolate preferred, or atropine) to block the muscarinic effects — bradycardia, bronchospasm, salivation and gut cramps; never give neostigmine alone.
- Give neostigmine only once spontaneous recovery has begun (ideally a train-of-four count of 4) — it is ineffective and potentially harmful during a deep block, and there is a ceiling effect beyond a maximum dose.
- Excess neostigmine itself causes weakness (cholinergic excess producing a depolarising-type block) — do not exceed the maximum dose chasing a fuller reversal.
- Neostigmine reversal is slower and less complete than sugammadex and is associated with residual blockade and postoperative pulmonary complications — consider sugammadex for the aminosteroids, especially after a deep block.
Meet the patient
At the end of a three-hour laparotomy maintained with rocuronium, the train-of-four shows four twitches with fade. The registrar reaches for neostigmine. Two questions must be answered before the syringe is given: has recovery genuinely begun, and is there an anticholinergic drawn up beside it?[6]
Neostigmine is the cheap, universal reversal for non-depolarising blocks — but three rules are absolute: never use it for sux, never give it during a deep block, and never give it without glycopyrrolate. Break any of the three and the patient is in danger.[6][5]
References7ShowHide
- [1]Tsai YF, et al. Sugammadex vs. neostigmine and the risk of postoperative pulmonary complications after upper gastrointestinal endoscopic procedures: a propensity score matched analysis of 15,730 patients Anaesthesia, 2026.PMID 42317106
- [2]Martins de Brito H, et al. The Effect of Sugammadex Versus Neostigmine on Postoperative Cognitive Recovery: A Systematic Review and Meta-Analysis Cureus, 2026.PMID 42317954
- [3]Leslie K, et al. Sugammadex versus neostigmine for reversal of neuromuscular blockade and postoperative pulmonary complications (SNaPP): an international, randomised, controlled, phase 4 trial Lancet Respir Med, 2026.PMID 42263720
- [4]Chen Z, et al. Half-dose neostigmine and low dose sugammadex as a reversal agent for vecuronium: a pilot randomized trial Anaesth Crit Care Pain Med, 2026.PMID 42217574
- [5]Tao JC, et al. Current status of neuromuscular reversal and neuromuscular monitoring in China: a cross-sectional survey BMC Anesthesiol, 2026.PMID 42185770
- [6]Krönauer T, Girrbach F, Simon P, Heller AR. [Muscle relaxation and neuromuscular monitoring : Current findings and recommendations for the clinical practice]. Anaesthesiologie, 2026.PMID 42334564
- [7]Zamani Kiasari A, et al. Comparing additive effect of dexmedetomidine and neostigmine to bupivacaine on postspinal anesthesia cesarean section induced pain intensity: A health promotion Approach J Educ Health Promot, 2026.PMID 42328403