ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Anticholinesterase — Neuromuscular Blockade Reversal Pregnancy: Use at caesarean section when indicated — fetal exposure minimal at clinical doses

Neostigmine (with Glycopyrronium)

Brand names: Neostigmine Methylsulfate

Adult dose

Dose: 2.5 mg IV (with glycopyrronium 0.5 mg IV)
Route: Intravenous
Frequency: Single dose at end of surgery
Max: 5 mg IV
Must be given with glycopyrronium (or atropine) to prevent muscarinic side effects (bradycardia, bronchospasm, excessive secretions). Confirm return of neuromuscular function with TOF ratio above 0.9 before extubation

Paediatric dose

Dose: 50-70 micrograms/kg IV (with glycopyrronium 10-15 micrograms/kg) micrograms/kg
Route: IV
Frequency: Single dose
Max: 2.5 mg neostigmine
Child: 50-70 micrograms/kg neostigmine with 10-15 micrograms/kg glycopyrronium

Dose adjustments

Renal

Reduce dose in severe renal impairment — reduced excretion prolongs effect

Hepatic

Use with caution

Paediatric weight-based calculator

Child: 50-70 micrograms/kg neostigmine with 10-15 micrograms/kg glycopyrronium

Clinical pearls

  • Sugammadex is now preferred over neostigmine for reversal of rocuronium or vecuronium — faster, more complete, and effective at any depth of block; neostigmine retained for atracurium reversal and when sugammadex unavailable
  • Neostigmine ceiling effect: maximum benefit at TOF ratio approximately 0.4; does not reliably achieve TOF ratio above 0.9 in deep block — wait for spontaneous partial recovery before administering
  • Residual neuromuscular blockade (RNMB): TOF ratio below 0.9 at extubation causes impaired airway reflexes and pharyngeal function — associated with aspiration and post-operative respiratory complications; quantitative TOF monitoring essential
  • Cholinergic crisis: excessive neostigmine doses cause depolarising blockade — weakness, fasciculations, bradycardia, bronchospasm; treat with atropine and mechanical ventilation
  • Always confirm adequate reversal with quantitative neuromuscular monitoring (TOF ratio above 0.9) before extubation — clinical tests (head lift, grip strength) are unreliable below TOF 0.7

Contraindications

  • Bowel or urinary obstruction
  • Depolarising NMBA (suxamethonium — neostigmine worsens phase 2 block)
  • Deep neuromuscular blockade (TOF count 0 — wait for at least 2 twitches before reversing)

Side effects

  • Bradycardia (if given without glycopyrronium)
  • Excessive secretions
  • Bronchospasm
  • Nausea and vomiting
  • Abdominal cramping
  • Weakness (paradoxical at high doses — cholinergic crisis)

Interactions

  • Suxamethonium (phase 2 block worsened)
  • Anticholinergics (glycopyrronium/atropine counteract muscarinic effects — always co-prescribe)
  • Aminoglycosides (may enhance residual neuromuscular blockade)

Monitoring

  • TOF ratio (quantitative neuromuscular monitoring)
  • Heart rate (bradycardia after injection)
  • Respiratory effort post-reversal
  • SpO2 post-extubation

Reference: BNFc; BNF 90; AAGBI Guidelines on Neuromuscular Blockade Monitoring; Blobner et al. (sugammadex vs neostigmine); Miller's Anaesthesia. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways