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Neostigmine for myasthenia gravis

Clinical author's note Michael Stewart 03/06/2024: Neostigmine bromide 15 mg tablets have been discontinued in the UK. Neostigmine injections are available and oral solutions may be available as special orders. Neostigmine tablets may still be available in other countries. This medicine leaflet is based on medical information available in the UK at the time of writing and is left here for reference purposes. Please also refer to the manufacturer's information supplied with your medicine.

Doses vary from person to person so take the tablets exactly as you are directed by your doctor.

The effect of neostigmine tablets lasts for about four hours. Take the tablets at suitable intervals during the day to give you the most strength when needed.

You are likely to be prescribed other medicines to take alongside neostigmine. If you are unsure about how to take any of your medicines, ask your doctor or pharmacist for advice.

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About neostigmine

Type of medicine

An anticholinesterase

Used for

Myasthenia gravis

Available as

Tablets (discontinued), injections or special order liquid medicines

Myasthenia gravis is a condition where your muscles become easily tired and weak. There is a fault in the way nerve messages are passed from your nerves to your muscles. As a consequence, your muscles are not stimulated properly, so do not tighten (contract) well. The muscles around the eyes are commonly affected first. Myasthenia gravis is an autoimmune disease. This means that the fault is due to a problem with your immune system. Your immune system (which normally protects your body from infections) mistakenly attacks itself.

Your brain normally sends messages down nerves to the muscles it wants to contract. The nerve endings then release a chemical called acetylcholine. Acetylcholine quickly attaches to small areas on your muscles, called receptors, and this triggers your muscles to contract. In most people with myasthenia gravis, the immune system blocks or damages these acetylcholine receptors. The acetylcholine cannot then attach to the receptor and so the muscle is less able to tighten.

Neostigmine works by slowing the breakdown of acetylcholine when it is released from nerve endings. This means that there is more acetylcholine available to attach to the muscle receptors and this improves the strength of your muscles.

Before taking neostigmine

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking neostigmine it is important that your doctor knows:

  • If you are pregnant or breastfeeding.

  • If you have asthma.

  • If you have any of the following conditions: epilepsy, Parkinson's disease, an overactive thyroid gland or low blood pressure.

  • If you have a heart condition, such as a slow heart rate, or if you have recently had a heart attack.

  • If you have a stomach ulcer.

  • If you have any problems with the way your kidneys work.

  • If you feel you may have a blockage in your intestines or if you have any difficulties passing urine.

  • If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

  • If you have ever had an allergic reaction to a medicine.

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How to take neostigmine

  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about neostigmine and will provide you with a full list of the side-effects which you may experience from taking it.

  • Take neostigmine tablets exactly as your doctor tells you to. Your dose will be printed on the label of the pack to remind you about what the doctor said to you. For adults, it is usual to take one or two tablets several times a day, as the effect of the tablets lasts for about four hours. Take the tablets at suitable intervals so that your muscles are strongest when you need to be the most active (for example, early in the morning and before meals). When neostigmine is prescribed for a child, the dose is calculated according to the age of the child.

  • Swallow the tablet(s) with a drink of water.

  • If you forget to take a dose at your usual time, take it when you remember. However, if it is nearly time to take your next dose when you remember then leave out the forgotten dose and take your next dose when it is due. Do not take two doses together to make up for a missed dose.

Getting the most from your treatment

  • Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress.

  • It is likely that you will be prescribed other medicines to take alongside neostigmine. You may be prescribed an immunosuppressant or corticosteroid medicine to help control your muscle symptoms. You may also be prescribed tablets to reduce some unwanted effects from taking neostigmine. This is because neostigmine can produce side-effects such as tummy (abdominal) cramp and diarrhoea. If you are unsure when or how to take all these medicines, ask your doctor or pharmacist to explain it to you again.

  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking neostigmine. This is important because neostigmine interferes with some medicines used during surgery.

  • If you buy any medicines, always check with a pharmacist that they are suitable for you to take with your other medicines.

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Can neostigmine cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with neostigmine. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common neostigmine side-effects

What can I do if I experience this?

Feeling sick (nausea) or being sick (vomiting), diarrhoea

Avoid rich or spicy foods, and drink plenty of water. If this becomes troublesome, speak with your doctor who may prescribe you a medicine to help control these symptoms

Tummy (abdominal) cramps, more saliva produced than usual

If either of these becomes troublesome, speak with your doctor for further advice

If you experience any other symptoms which you think may be due to the tablets, speak with your doctor or pharmacist for further advice.

How to store neostigmine tablets

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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