Medicines & Supplements A to Z > Neostigmine


Last updated on 21/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  

GENERIC NAME: Neostigmine

CHINESE NAME: 新斯狄明, 新斯的明

BRAND NAME(S) IN HONG KONG: Neostigmine methylsulfate

DRUG CLASS: Central nervous system agents

SUB CLASS: Acetylcholinesterase inhibitors

USED FOR: Myasthenia gravis, Neuromuscular disorders, Postoperative urinary retention

AVAILABLE DOSAGE FORMS: 2.5 mg/ml (injections)

What is Neostigmine for?

Neostigmine belongs to a class of medications called central nervous system agents inhibiting an enzyme acetylcholinesterase to slow down the breakdown of a neurotransmitter acetylcholine. Neostigmine is used for treating myasthenia gravis, neuromuscular disorders and postoperative urinary retention.

How to use it?

Neostigmine is injected through the veins and muscle or under the skin as neostigmine methylsulphate. 

Myasthenia gravis
Intramuscular injection: The initial dose is 0.1 mg followed by 0.05-0.25 mg or 0.03 mg/kg every 2-4 hours.

Child below 12 years of age
Intramuscular or subcutaneous injection: 0.2-0.5 mg repeated at appropriate intervals.

Intramuscular or subcutaneous injection: 0.5-2.5 mg repeated at appropriate intervals to a total daily dose of 5-20 mg.

Paralytic ileus and postoperative urinary retention
Intramuscular or subcutaneous injection: 0.125-1 mg.

Intramuscular or subcutaneous injection: 0.5-2.5 mg when needed.

Reversal of neuromuscular blockade
Child and adult
Intravenous injection: 0.05-0.07 mg/kg as IV bolus over 60 seconds.

What are the side effects of Neostigmine?

Common side effects of Neostigmine include tachycardia, dizziness, diarrhoea, muscle pain, bronchospasm and excessive tear.

Who should not take Neostigmine?

– People allergic to Neostigmine or any component of the formulation.
– Patients with peritonitis or mechanical obstruction of the intestinal or urinary tract.

Pharmacist Tips:

– Cholinergic toxicity may happen when taking acetylcholinesterase inhibitors like Neostigmine .Signs like diarrhea, diaphoresis, frequent urination, miosis, bronchospasm, bronchorrhea, vomiting and excessive tear and saliva. Report to your physician as soon as possible if these symptoms appear.

Common dosing schedule:
Neostigmine injections are prescribed in institutions by the physicians.

This schedule is for reference only, adjustments may be made according to individual needs. 

Some common medications Neostigmine may interact with:
– Beta-blockers, e.g. Bisoprolol, Metoprolol, Propranolol
– Anticholinergic agents, e.g. Atropine, Benztropine, Benzhexol
– Cholinergic agonists, e.g. Pilocarpine, Donepezil, Parathion
– Corticosteroids, e.g. Hydrocortisone, Dexamethasone, Prednisolone

Neostigmine may interact with many other medications. Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Neostigmine in Hong Kong?

In Hong Kong, Neostigmine is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of Neostigmine in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.