Pyridostigmine bromide oral
- Drugs List
- Therapeutic Indications
- Dosage
- Contraindications
- Precautions and Warnings
- Pregnancy and Lactation
- Side Effects
- Monograph
Presentation
Oral formulation of pyridostigmine bromide.
Drugs List
Therapeutic Indications
Uses
Myasthenia gravis
Paralytic ileus
Post operative urinary retention
Dosage
Adults
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.
Children
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.
Neonates
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.
Contraindications
Galactosaemia
Gastrointestinal obstruction
Hereditary fructose intolerance
Urinary obstruction
Precautions and Warnings
Elderly
Vagotonia
Asthma
Atrioventricular block
Bradycardia
Breastfeeding
Cardiac arrhythmias
Chronic obstructive pulmonary disease
Epileptic disorder
Glucose-galactose malabsorption syndrome
Hyperthyroidism
Hypotension
Lactose intolerance
Parkinson's disease
Peptic ulcer
Pregnancy
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
Pregnancy
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.
Lactation
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
Arrhythmias
Atrioventricular block
Bradycardia
Bronchoconstriction
Diarrhoea
Disturbances in accommodation
Fasciculation
Gastro-intestinal motility increased
Hyperhidrosis
Hypotension
Increased bronchial secretions
Increased lacrimation
Miosis
Muscle hypotonia
Muscle weakness
Muscular cramps
Nausea
Rash
Salivation changes
Syncope
Tachycardia
Tremor
Urinary urgency
Vomiting
Overdosage
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 ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).
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: www.nice.org.uk Last accessed: 23 June 2022
Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content
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.