Myasthenia gravis

30-120mg, doses to be given at suitable intervals throughout the day. It is inadvisable to exceed 450mg daily in order to avoid acetylcholine receptor down-regulation.

Prescribing Notes:

Treatment for myasthenia gravis should only be initiated on specialist advice.
A number of drugs, including some antibiotics, may exacerbate myasthenia gravis. The Myaware website provides useful information on this matter. More detailed and up-to-date information on individual medicines may be obtained from hospital Medicines Information centres and where appropriate the relative risks should be discussed with the patient’s neurologist.
Edrophonium is used in hospital as a diagnostic test for myasthenia gravis.
Pyridostigmine bromide 60mg orally is approximately equivalent to neostigmine 15mg orally, or 1-1.5mg by intramuscular or subcutaneous injection.
Pyridostigmine bromide has a longer duration of action than neostigmine and is first choice for oral use. Neostigmine is useful in patients requiring parenteral treatment.
An antimuscarinic (e.g. propantheline 15mg orally as required up to 3 times daily or adjusted to individual circumstances) may be required to treat side-effects such as sweating, colic, excessive salivation and diarrhoea.
In more severe cases, prednisolone ± a corticosteroid-sparing agent (azathioprine) may be prescribed under specialist supervision for myasthenia gravis.

History Notes

27/10/2022

East Region Formulary content agreed.

Dose as per specialist.

Prescribing Notes:

Treatment for myasthenia gravis should only be initiated on specialist advice.
A number of drugs, including some antibiotics, may exacerbate myasthenia gravis. The Myaware website provides useful information on this matter. More detailed and up-to-date information on individual medicines may be obtained from hospital Medicines Information centres and where appropriate the relative risks should be discussed with the patient’s neurologist.
Edrophonium is used in hospital as a diagnostic test for myasthenia gravis.
Pyridostigmine bromide 60mg orally is approximately equivalent to neostigmine 15mg orally, or 1-1.5mg by intramuscular or subcutaneous injection.
Pyridostigmine bromide has a longer duration of action than neostigmine and is first choice for oral use. Neostigmine is useful in patients requiring parenteral treatment.
An antimuscarinic (e.g. propantheline 15mg orally as required up to 3 times daily or adjusted to individual circumstances) may be required to treat side-effects such as sweating, colic, excessive salivation and diarrhoea.
In more severe cases, prednisolone ± a corticosteroid-sparing agent (azathioprine) may be prescribed under specialist supervision for myasthenia gravis.
Congenital Myasthenic Syndromes may be treated with pyridostigmine under specialist advice. Other treatments such as salbutamol and 3,4-diaminopyridine may also be considered.

History Notes

09/11/2023

East Region Formulary content agreed.