neostigmine methylsulfate at a glance
Medicine class
Reversible cholinesterase inhibitor
Form
Sterile solution given by intravenous, intramuscular or subcutaneous injection, depending on the indication
Important safety point
Can slow the heart and increase airway, salivary and gastrointestinal secretions
What is neostigmine methylsulfate used for?
The selected product is licensed for:
Treating muscle weakness caused by myasthenia gravis.
Reversing residual paralysis caused by non-depolarising neuromuscular blocking medicines after surgery.
Treating paralytic ileus.
Treating postoperative urinary retention.
Specialist treatment of severe paroxysmal supraventricular tachycardia that has not responded to conventional treatment.
How does neostigmine methylsulfate work?
Neostigmine temporarily blocks acetylcholinesterase, the enzyme that normally breaks down acetylcholine. This increases acetylcholine at nerve–muscle junctions, strengthening skeletal-muscle activation and increasing parasympathetic activity in organs such as the bowel and bladder.
neostigmine methylsulfate preparations and strengths
Injection
Route: Parenteral
Strengths: 2.5 mg/1 mL
How to take neostigmine methylsulfate
This formulation is an injection administered by a healthcare professional. The route depends on why it is being used, and intravenous administration is given slowly. Appropriate monitoring and a medicine such as atropine must be available to manage excessive cholinergic effects.
Do not inject or alter treatment unless specifically trained and instructed by the responsible clinical team.
Tell the clinical team about myasthenia gravis, asthma, heart-rhythm problems, bowel or urinary problems and all current medicines before administration.
Discard any unused solution from an opened ampoule.
neostigmine methylsulfate side effects
Common or expected effects
- Nausea, vomiting, diarrhoea, abdominal cramps and increased saliva.
- Sweating, increased tears, small pupils, muscle spasms and urinary incontinence.
- The available product information does not establish frequencies for these effects.
Get urgent medical advice
- Slow heartbeat, impaired cardiac conduction, heart block, low blood pressure or cardiac arrest.
- Bronchospasm, increased airway secretions or breathing difficulty.
- Severe allergic reaction, including angioedema or anaphylaxis.
- Cholinergic crisis, with increasing secretions, cramps, twitching, weakness or paralysis.
neostigmine methylsulfate in pregnancy
Evidence in pregnancy is limited. The product information advises weighing potential benefit against risk; specialist review is particularly important because myasthenia gravis can fluctuate and excessive treatment may cause cholinergic crisis.
neostigmine methylsulfate while breastfeeding
Only negligible amounts are expected in breast milk, but infant effects should still be considered. Limited published evidence regards use as potentially acceptable, with observation of newborns for effects such as abdominal cramps.
neostigmine methylsulfate interactions
Clinicians should review all medicines affecting neuromuscular transmission, heart rate or cholinergic activity.
Non-depolarising neuromuscular blockers
Neostigmine antagonises their effects; this is intentionally used to reverse residual paralysis after surgery.
Suxamethonium and other depolarising muscle relaxants
Neostigmine may prolong or intensify the initial neuromuscular block; concomitant use is contraindicated for the selected product.
Atropine or glycopyrronium
These counter muscarinic effects such as slow heart rate and excessive secretions when neostigmine is used for neuromuscular-block reversal.
Common questions about neostigmine methylsulfate
Answers are fully visible for fast scanning and source review.
Is neostigmine methylsulfate the same as pyridostigmine?
No. Both inhibit cholinesterase, but they differ in formulation and duration of action. In myasthenia gravis practice, neostigmine injection may be considered when swallowing is difficult.
Why is atropine given with neostigmine methylsulfate?
Atropine blocks unwanted muscarinic effects such as a slow heartbeat and excessive secretions while allowing neostigmine's effect at skeletal muscle.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.