Medication: Methyldopa
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Please note that none of the information in this document is a substitute for advice from your healthcare professional. Please always consult a medical professional and always check the Patient Information Leaflet that is provided with your medication for more detailed information.
Methyldopa: A quick overview
- Used in some people with hyperadrenergic PoTS
- Reduces excessive “fight-or-flight” nervous system activity
- Taken daily, not occasionally
- Longer-acting and steadier blood levels than clonidine
- Can worsen fatigue and brain fog in some people
- Usually prescribed and monitored by a specialist
What is Methyldopa?
Methyldopa is a medication that acts on the central nervous system to reduce excessive sympathetic (“fight-or-flight”) activity.
It is sometimes used in people with:
- Hyperadrenergic PoTS
- Orthostatic hypertension (a rise in blood pressure on standing) alongside a fast heart rate
By calming this overactive response, methyldopa can reduce symptoms when standing for some people.
Who is usually prescribed Methyldopa?
Methyldopa is not usually a first-line treatment for PoTS.
It may be considered if you:
- Have not responded well to other treatments
- Have particularly high sympathetic nervous system activity
Because methyldopa can increase fatigue and brain fog, it is used cautiously.
What does “off-licence” mean for me?
Methyldopa is officially licensed in the UK for the treatment of:
- High blood pressure (hypertension)
Its use in PoTS is considered off-licence because PoTS is not a formally approved indication for this drug.
This means:
- It must be prescribed specifically for you by a healthcare professional familiar with PoTS who must take on added responsibilities compared to prescribing licensed drugs
- A healthcare professional is responsible for monitoring your response
How does Methyldopa help with PoTS symptoms?
Methyldopa reduces sympathetic (“fight-or-flight”) signals from the brain.
This can:
- Relax blood vessels
- Lower blood pressure
- Reduce adrenaline-driven symptoms
Compared to clonidine, methyldopa is normally better supported by people with PoTS since it:
- Acts more slowly
- Lasts longer
- Avoids sudden “peaks and troughs” associated with fast acting medicines
What does the evidence show?
- Evidence is based on small clinical studies
- Most research involves severe or treatment-resistant PoTS
- Reported benefits are short term
- Long-term safety data in PoTS are limited
How and when is it taken?
Methyldopa is typically taken daily as a tablet:
- • Dosing usually starts very low, often 125 mg taken before bed
- • If tolerated, the dose may be increased slowly to 125 mg or 250 mg twice daily
- • Doses above 250 mg twice daily are uncommon in PoTS
Always take methyldopa exactly as directed by your doctor, dosing may vary depending on your individual situation.
Important considerations
Monitoring
- Blood tests are usually needed before starting
- Liver function and blood counts are often checked during the first 6–12 weeks
Drowsiness
- Methyldopa can cause significant drowsiness
- Avoid driving or operating machinery until you know how it affects you
- Methyldopa will add to the effects of other central nervous system depressants like alcohol and antihistamines
Lifestyle
- Methyldopa lowers blood pressure and can lead to fatigue and exercise intolerance
- Your doctor may adjust advice on:
- Salt and fluid intake
- Exercise
Always follow advice from your care team and contact them if you are unsure.
What are the side effects of Methyldopa?
The most common side effects for PoTS patients are fatigue and brain fog.
Other common side effects include:
- Drowsiness and sedation
- Low blood pressure (hypotension)
- Dry mouth and eyes
- Headaches
- Swelling of the feet or lower legs
Rarer but important side effects include:
- Mental depression or anxiety
- Nightmares or unusually vivid dreams
- Dark or amber urine
- Diarrhoea or stomach cramps (severe or continuing)
- Fever, chills, troubled breathing, and fast heartbeat
- General feeling of discomfort or illness or weakness
- Joint pain
Seek urgent medical help if you experience:
- Unexplained fever, which may be a sign of a serious reaction or liver disorder
- Jaundice (yellowing of the eyes or skin)
- New or worsening mental depression or anxiety
- Severe diarrhoea or stomach cramps
How do I get and store Methyldopa?
- Methyldopa is typically prescribed initially by specialists familiar with PoTS
- Follow-up prescribing often managed by your GP
- Available in most large pharmacies with an NHS or private prescription
Store your medication in a closed container at room temperature, protected from direct sunlight, and out of children’s reach. Verify expiry dates before use.
Useful links
Everything you need to know on Methyldopa:
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This information is general information about PoTS and is not an alternative to medical advice from your doctor or other healthcare professional. You must always consult your doctor or healthcare professional.
Production date 22/06/2026
Next review 22/06/2029
Version 1.4