Medication: Pyridostigmine

What Is Pyridostigmine?

Pyridostigmine is a medication used off-licence to manage the symptoms of Postural Tachycardia Syndrome (PoTS). It may be recommended when lifestyle changes or other medications, such as beta-blockers, haven’t sufficiently improved your symptoms.

What Does “Off-Licence” Mean?

In the UK, pyridostigmine is officially approved to treat conditions such as myasthenia gravis, an autoimmune condition affecting muscle strength. Using pyridostigmine for PoTS is considered off-licence because it is not officially approved for this purpose.

How Does Pyridostigmine Work?

Pyridostigmine works by enhancing communication between nerves and muscles by blocking the breakdown of a chemical called acetylcholine. In PoTS, this action helps to stabilise the heart rate and improve circulation, potentially reducing symptoms like rapid heartbeat, dizziness, and fatigue when standing. Combining pyridostigmine with lifestyle adjustments often enhances its effectiveness.

Lifestyle Changes That Help

To optimise the benefit of pyridostigmine, it is important to incorporate lifestyle changes including:

• Drinking more fluids and increasing salt intake to maintain blood volume
• Eating smaller, more frequent meals
• Using compression garments to improve circulation

For additional lifestyle advice, visit the PoTS UK general advice page.

How Do You Take Pyridostigmine?

Pyridostigmine is available as tablets, commonly under the brand name “Mestinon,” usually prescribed in doses ranging from 30mg to 60mg taken up to three times daily. It is recommended to take the tablets with food to minimise stomach upset.

Who Should Not Take Pyridostigmine?

Only take pyridostigmine if prescribed by your doctor. It may not be suitable if you have:

• Severe asthma or respiratory issues
• Heart rhythm disorders
• Intestinal blockages or severe digestive issues
• Urinary tract obstruction

Consult your doctor about potential interactions with other medications or herbal supplements you might be taking.

Pyridostigmine can be used cautiously in pregnancy or breastfeeding, but always under close medical supervision.

What Are The Side Effects?

Common side effects (affecting more than 1 in 100 people) include:

• Nausea and stomach cramps
• Diarrhoea
• Increased saliva production
• Sweating

Less common side effects include:

• Muscle twitching
• Weakness
• Slow heart rate

Rare but serious side effects such as severe breathing difficulties or allergic reactions require immediate medical attention. Report any concerning symptoms promptly to your healthcare provider.

Monitoring During Treatment

Regular medical reviews, including heart rate, blood pressure, and symptom diaries, help assess effectiveness and side effects. Your healthcare professional will guide you regarding necessary monitoring.

How To Get And Store Pyridostigmine

Since pyridostigmine is prescribed off-licence for PoTS, it is usually initiated by a specialist, after which some GPs may continue prescribing. Obtain pyridostigmine through hospital or community pharmacies via NHS or private prescriptions.

Store in a cool, dry place, away from sunlight and out of reach of children, ensuring you check the expiry date regularly.

This web page is a brief summary of Pyridostigmine. Always check the Patient Information Leaflet that is provided with your medication for more detailed information.