Neostigmine is a medicine used at the end of surgeries to reverse the effect of muscle relaxants, allowing the patient to breathe and move normally. It is also used in acute bowel and urinary problems from lack of tone.
Also known as: Prostigmina
Magnesium sulphate depresses neuromuscular transmission and can blunt reversal with neostigmine.
Mg2+ inhibits presynaptic acetylcholine release, counteracting the effect of cholinesterase inhibition by neostigmine (labels).
Muscle strength (head lift, spontaneous capnography), Mg2+.
Residual weakness, re-intubation, respiratory depression.
Assess reversal clinically and by tremography; correct hypermagnesaemia; ventilatory support until full reversal.
DailyMed — Neostigmine Methylsulfate Injection and Magnesium Sulfate Injection labels: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4eab6184-1771-4c15-a127-4eb3e47affc2
No documented food or drink interactions.
Anticholinesterases increase peristalsis — contraindicated in mechanical obstruction and paralytic ileus (rupture risk).
Exclude mechanical obstruction before use as prokinetic/residual curarisation reversal.
Prontuário Terapêutico INFARMED (neostigmine — mechanical bowel obstruction).
Neostigmine worsens urinary retention in BPH (increases sphincter tone).
Ask about urinary symptoms before administration.
EMC-UK — neostigmine SmPC 4.4 (urinary retention, BPH).
No specific Annex 1 entry; neostigmine is used for neuromuscular blockade reversal (with atropine/glycopyrrolate) in caesarean sections with no teratogenicity signal. In the 3rd trimester and near term, high doses may cause fetal bradycardia and, in infants of myasthenic mothers, transient neonatal weakness (neonatal myasthenic syndrome).
Compatible for standard anaesthetic use; monitor fetal heart rate and newborn neuromuscular function if high doses near term.
Little passes into milk; compatible — monitor the infant for cholinergic symptoms if the mother receives repeated doses.
EMC-UK (MHRA) — Neostigmine SmPC: https://www.medicines.org.uk/emc/product/2937/smpc (section 4.6). Prontuário Terapêutico INFARMED — 13.2 (Neuromuscular blockers and antidotes).
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Reversal of non-depolarising neuromuscular blockade within 10–20 min; ↑ peristalsis and bladder tone.
Reversible acetylcholinesterase inhibition: ↑ acetylcholine in the synaptic cleft, competitively displacing the blocker from the nicotinic receptor (indirect agonist action).
IV: immediate action; IM: peak in 20–30 min; oral: poor absorption (1–2%).
Hepatic esterase hydrolysis; predominant renal excretion (50% unchanged).
~ 1–2 h (IV).
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
