Myasthenia Gravis Medical ID: Medicines to Avoid and Myasthenic Crisis

Myasthenia gravis rarely looks the same two days running. A drooping eyelid in the evening, a voice that fades mid-sentence, a meal that becomes hard to finish, arms that tire brushing your hair: these come and go, which is exactly why a stranger in an emergency will not recognise them. This guide explains what MG is, which medicines Australian MG organisations ask doctors to use with caution, what a myasthenic crisis looks like, and what your medical ID should say.

What myasthenia gravis is

According to healthdirect, myasthenia gravis is a rare autoimmune disease of the neuromuscular system. It causes a breakdown in communication between nerves and muscles, so the muscles you control voluntarily become weak. Those include:

• muscles that control eye and eyelid movements — drooping eyelids, blurred or double vision
• muscles for chewing, talking and swallowing
• muscles involved in breathing, including the diaphragm and the muscles between the ribs
• muscles in the arms and legs, which can make walking unsteady

Symptoms can appear suddenly or over weeks, and the weakness can come and go. healthdirect lists triggers including emotional stress, fever, pushing yourself too hard, some medicines and illness.

Myasthenic crisis: when MG is an emergency

healthdirect describes a myasthenic crisis as a potentially life-threatening emergency in which the muscles that control breathing become weak. You may be short of breath or unable to breathe properly, and in severe cases you may need a ventilator. An infection, a fever, emotional stress or a reaction to a medicine can trigger it.

Swallowing weakness brings its own risk. healthdirect warns that food and drink can go into the lungs — aspiration — which can cause pneumonia. If someone is choking, the steps in our choking first aid guide apply.

Medicines to use with caution in MG

Myasthenia Alliance Australia, working with the state associations, publishes a short list of medicines that can worsen MG symptoms, as an aid for patients and their doctors. It groups them like this:

Look at where those medicines are used: antibiotics for an infection, magnesium on a ward, sedatives in an emergency department, muscle relaxants and anaesthetic agents before an operation. An infection is also a trigger for a crisis. The moment you are most likely to need one of these drugs is the moment you are least able to mention your MG. If you are ever put under general anaesthesia, the team also needs to know; our anaesthetic alert medical ID guide covers how to record anaesthetic warnings.

For everyday prescribing, healthdirect’s advice is to check with your doctor before taking any new medicine — including medicines another doctor prescribes, over-the-counter medicines, complementary medicines and traditional remedies.

Who reads an MG medical ID

Australian resuscitation guidance tells rescuers to look. ANZCOR Guideline 2 includes, in the initial assessment of an emergency, checking for “physical (eg. alert jewellery) or electronic alert devices (eg. smartphone application) that may be relevant to assessment or management”. For MG, that means:

• A bystander who sees a drooping eyelid, slurred speech or weakness and may not recognise them as MG. The word “myasthenia” tells them breathing is the thing to watch.
• A paramedic choosing pain relief or sedation, and deciding how urgently your breathing needs support.
• An emergency doctor choosing an antibiotic or a drug for intubation, who needs your neurologist’s number.

Slurred speech and facial weakness are also signs of stroke, and a new stroke must never be assumed away. The stroke F.A.S.T. guide explains why sudden new symptoms still mean calling 000.

What a myasthenia gravis medical ID should say

healthdirect suggests the medicine card you carry includes your name, date of birth, your doctor, other medical conditions and an emergency contact. A medical ID lets you carry all of that, and more, behind one number.

On the band

• MYASTHENIA GRAVIS
• CHECK DRUGS — BREATHING MAY WEAKEN
• Your membership number, so the rest can be read

In the profile

• Your MG medicines by name, dose and time — and any immunosuppressant, because live vaccines may be unsuitable for people who are immunosuppressed, as the Alliance list notes.
• A line reading “Medicines to use with caution: see Myasthenia Alliance Australia list”, and any specific drug that has worsened your MG before.
• Whether you have had a thymectomy or a previous myasthenic crisis, and how it was treated.
• Your swallowing and breathing baseline: what is normal for you on a bad day.
• Your neurologist and hospital, and your GP.
• Emergency contacts who know your pattern of weakness.

Support in Australia

Myasthenia Alliance Australia brings together the state associations. The Myasthenia Gravis Association of Queensland runs a freecall line on 1800 802 568 and publishes its own drugs and MG page. For keeping your medicines list accurate, see our guide to managing your medication.

Keeping it current

MG treatment changes as the disease does. Update your record whenever a medicine or dose changes, after any crisis or admission, after surgery such as thymectomy, and after every neurology review. A current list is what lets an unfamiliar team choose the right antibiotic at 3am.

FAQs

Sources

• healthdirect — Myasthenia gravis — (reviewed July 2024) symptoms, triggers, myasthenic crisis, medicine card and medical alert jewellery.
• Myasthenia Alliance Australia — Drugs to be used with caution in myasthenia gravis — the caution list and its disclaimer.
• Myasthenia Alliance Australia — Drugs and MG — background to the list.
• Myasthenia Gravis Association of Queensland — Drugs and MG — the Queensland association’s version and freecall support.
• ANZCOR Guideline 2 — Managing an Emergency — checking for alert jewellery and devices.

Disclaimer: This article is general information about recording myasthenia gravis details for emergencies, not medical advice. The medicines named are taken from a published Australian caution list; whether any medicine is appropriate is a decision for your doctor. Never stop or change MG medicines without medical advice. In an emergency, always call Triple Zero (000). For non-urgent health advice, call healthdirect on 1800 022 222 (NURSE-ON-CALL 1300 60 60 24 in Victoria, 13 HEALTH 13 43 25 84 in Queensland).

Related guides

• Anaesthetic alert medical ID
• Stroke signs and F.A.S.T. first aid
• Choking first aid
• Tips to manage your medication
• What is MedibandPlus?