Myasthenia Gravis in Acute Care

Contact on call neurology registrar as soon as possible to inform of any patient admitted with a history of myasthenia gravis (MG).

Symptoms of MG 

These include:

  • Difficulty swallowing, speaking or chewing
  • Double vision and ptosis
  • Neck and limb weakness
  • Type II respiratory failure.

Important points

  • It is crucial not to withhold MG medicines for any significant length of time, i.e. >2 hours, or to miss any doses of pyridostigmine or steroids as there is a risk of myasthenic crisis.
  • Before prescribing any new medicine, check if the medicine may affect patients with MG by referring to the guideline entitled ‘Myasthenia Gravis or Lambert-Eaton Myasthenia Syndrome – Medicines that may affect patients'. This can be found on NHSGGC StaffNet / Clinical Info / Clinical Guidelines Directory and search for 'myasthenia gravis'.
  • High risk situations include: nil by mouth status, infection and surgical procedures.


  • It is important for pyridostigmine to be administered at exact times. Ensure no missed doses.
  • Where a patient does not have an individual supply of pyridostigmine (Mestinon®), this must be obtained via pharmacy or on call pharmacist via switchboard if out of hours.
  • Overdose of pyridostigmine can lead to cholinergic crisis (refer to Pyridostigmine Q&A on NHSGGC  StaffNet / Acute / Regional Services / Neuro-sciences Institute / Neurology / Myasthenia Gravis).

Nil by mouth

  • Administration of medication via nasogastric (NG) feeding tube is the preferred option in patients who are unable to swallow. Pyridostigmine and prednisolone (not enteric coated, E/C) tablets can be crushed and mixed with water.
  • Any delays in passing NG tube, or if NG insertion is not possible, seek senior medical and neurology advice as soon as possible.


  • Certain antimicrobials should be avoided (e.g. gentamicin) or used with caution (refer to guideline entitled 'Myasthenia Gravis or Lambert-Eaton Myasthenia Syndrome – Medicines that may affect patients' on NHSGGC StaffNet / Clinical Info / Clinical Guidelines Directory and search for 'myasthenia gravis').
  • Do not automatically double steroid dose in the context of infection in a patient with MG (see information below).

Minor infection

  1. Continue regular immunosuppressant drugs.
  2. Stable MG patients may not require any change in steroid dose.

Severe infection or sepsis

  1. Withhold regular immunosuppressant drugs (and discuss with MG team).
  2. Consider increasing steroid dose after consulting with MG/neurology team.

Patients with stable MG can usually revert to baseline steroid dose once infection is treated (provided <3 weeks on higher dose). Patients with active MG may require slower reduction in steroid dose (consult MG team).

Patients undergoing surgical procedures

  • Patients should continue with regular medication for MG pre- and post-operatively.
  • Discuss on a case by case basis with an anaesthetist and MG team.


Content last reviewed March 2021