Medication Information Leaflet

What is this medication for?

Pyridostigmine is used to treat the symptoms of myasthenia gravis, which is an immune system related condition that causes weakness in certain muscles. These include muscles around the eyes, jaw, face, neck, arm or leg and muscles that help with breathing. 

How should I take/use this medication?

  • Do not stop taking your medication without checking with your healthcare professional.
  • This medication should be taken with or after food to reduce stomach upset.

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose. 

What precautions should I take?

Inform your healthcare professional if: 
  • You are allergic to this medication or any of the other ingredients of this medication
  • You have a history of:
    • Heart condition
    • Kidney condition
    • Lung condition such as asthma
    • Glaucoma (high pressure in eyes)
    • Urinary condition
  • You are pregnant, planning to become pregnant, or breastfeeding 
  • You are taking any other medications, including supplements, traditional medications and herbal remedies. 

What are some common side-effects of this medication?

  • Drowsiness
    • Avoid driving or engaging in activities that require concentration
  • Blurred vision
    • Avoid driving or engaging in activities that require concentration
  • Stomach upset
    • Take this medication with or after food to reduce stomach upset
  • Diarrhea
    • Drink more water to replace the loss of fluids
  • Increased saliva
  • Increased sweating
  • Increased frequency of urination
  • Muscle twitching

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following: 
  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

Inform your doctor if you develop any of these possible symptoms of worsening myasthenia gravis:
  • Weakness of the eye muscles
  • Drooping of one or both eyes
  • Trouble swallowing or breathing
  • Trouble with speaking 
  • Severe muscle weakness

What food or medication should I avoid when I take this medication?

Avoid drinking alcohol while taking pyridostigmine as it may cause excessive drowsiness. 

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children. 

How should I throw away this medication safely?

Pack this medication into a black trash bag and seal it tightly before throwing it into the rubbish chute or bin.


If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Sept 2021

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