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
- Difficulty swallowing, speaking or chewing
- Double vision and ptosis
- Neck and limb weakness
- Type II respiratory failure.
- 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).
- Continue regular immunosuppressant drugs.
- Stable MG patients may not require any change in steroid dose.
Severe infection or sepsis
- Withhold regular immunosuppressant drugs (and discuss with MG team).
- 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