This site is intended for UK healthcare professionals
Medscape UK Univadis Logo
Medscape UK Univadis Logo

Pyridostigmine bromide oral


Oral formulation of pyridostigmine bromide.

Drugs List

  • MESTINON 60mg tablets
  • pyridostigmine bromide 12mg/ml oral solution sugar-free
  • pyridostigmine bromide 60mg tablets
  • Therapeutic Indications


    Myasthenia gravis
    Paralytic ileus
    Post operative urinary retention



    Myasthenia Gravis
    30mg to 120mg given throughout the day when maximum strength is needed such as on rising and before mealtimes.
    The duration of action of a dose during the day is usually 3 to 4 hours, with a longer effect (6 hours) with a dose taken at bedtime
    Some patients may require higher doses.
    The total daily dose may range from 300mg to 1200mg.

    Paralytic ileus; Post-operative urinary retention
    60mg to 240mg daily.


    Myasthenia Gravis
    Children aged 12 to 18 years
    (See Dosage; Adult)
    Children aged 6 to 12 years
    Initial dose: 60mg
    Maintenance dose: 30mg to 360mg daily.
    Children aged under 6 years
    Initial dose: 30mg
    Maintenance dose: 30mg to 360mg daily.

    Dosage should be increased gradually, in increments of 15mg to 30mg daily, until symptoms controlled.

    The following alternative unlicensed dosing schedule may be suitable:

    Children aged 12 to 18 years
    Initial dose: 30mg to 90mg every 4 to 6 hours.
    If total daily dose exceeds 360mg, consider immunosuppressant therapy. Total daily dose exceeding 450mg can down-regulate acetylcholine receptors.
    Children aged 1 month to 12 years
    Initial dose: 0.5mg/kg to 1mg/kg every 4 to 6 hours.
    Maintenance dose: If necessary, increase up to 1.2mg/kg every 4 hours. Maximum dose of 60mg every 4 hours.
    Dose can be increased every 3 to 4 days or more if monitoring for side effects during inpatient treatment.

    Paralytic ileus; Post-operative urinary retention
    15mg to 60mg daily.
    Frequency of doses may be varied according to the needs of the patient.


    The following unlicensed dosing schedule may be suitable:
    Treatment of myasthenia gravis
    Initial dose: 0.5mg/kg to 1mg/kg every 4 to 6 hours.
    Maintenance dose: If necessary, increase up to 1.2mg/kg every 4 hours. Give 30 to 60 minutes before feeds.
    Dose can be increased every 3 to 4 days or more if monitoring for side effects during inpatient treatment.

    Patients with Renal Impairment

    Pyridostigmine is mainly excreted unchanged by the kidney, therefore lower doses may be required in patients with renal disease and treatment should be based on titration of drug dosage to effect.

    Additional Dosage Information

    When relatively large doses of pyridostigmine are taken by myasthenic patients it may be necessary to give atropine or other anticholinergic drugs to counteract the muscarinic effects. It should be noted that slower gastro-intestinal motility caused by these drugs may affect the absorption of pyridostigmine.

    Down-regulation of acetylcholine receptors possible if total daily dose exceeds 450mg.


    Gastrointestinal obstruction
    Hereditary fructose intolerance
    Urinary obstruction

    Precautions and Warnings

    Atrioventricular block
    Cardiac arrhythmias
    Chronic obstructive pulmonary disease
    Epileptic disorder
    Glucose-galactose malabsorption syndrome
    Lactose intolerance
    Parkinson's disease
    Peptic ulcer
    Recent myocardial infarction
    Renal impairment

    Distinguish between cholinergic and myasthenia crisis
    Reduce dose in patients with renal impairment
    Sodium content of formulation may be significant
    Advise ability to drive/operate machinery may be affected by side effects
    Oral liquid contains propylene glycol
    Oral solution contains glycerol
    Oral solution contains sodium benzoate
    Presentations with sorbitol unsuitable in hereditary fructose intolerance
    Some formulations contain lactose
    High doses (>450mg daily) may cause acetylcholine receptor down regulation

    In all patients the possibility of 'cholinergic crisis' (due to pyridostigmine overdosage) and its differentiation from 'myasthenic crisis' (due to increased disease severity), must be borne in mind. Both types of crisis result in increased muscle weakness, but whereas myasthenic crisis may require more intensive anticholinesterase treatment, cholinergic crisis calls for immediate discontinuation of this treatment and institution of appropriate supportive measures, including respiratory assistance.

    Pregnancy and Lactation


    Use pyridostigmine bromide with caution during pregnancy.

    The manufacturer advises caution if pyridostigmine bromide is used during pregnancy. Excessive doses should be avoided and any exposed infants should be monitored. Animal studies have indicated fetotoxicity and effects on the offspring. At the time of writing there is limited published information regarding the use of pyridostigmine bromide during pregnancy. Potential risks are unknown.


    Use pyridostigmine bromide with caution during breastfeeding.

    The manufacturer advises caution if pyridostigmine bromide is used when breastfeeding. Available data indicates pyridostigmine bromide is expressed in human breast milk, the quantity and the effects on exposed infants are unknown.

    Side Effects

    Abdominal cramps
    Allergic reaction
    Atrioventricular block
    Disturbances in accommodation
    Gastro-intestinal motility increased
    Increased bronchial secretions
    Increased lacrimation
    Muscle hypotonia
    Muscle weakness
    Muscular cramps
    Salivation changes
    Urinary urgency


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: September 2020

    Reference Sources

    Summary of Product Characteristics: Mestinon 60mg Tablets. Meda Pharmaceuticals. Revised February 2018.

    Summary of Product Characteristics: Pyridostigmine Bromide 12mg/ml Oral solution. Horizon Pharmaceuticals Limited. Revised February 2022.

    NICE Evidence Services Available at: Last accessed: 23 June 2022

    Access the full UK drug database with a FREE Medscape UK Account
    It takes just a few minutes, and you’ll get unlimited access to information on over 11,000 UK drugs.
    Register for Free

    Already a member? Log in

    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

    FDB Logo

    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.