Medication: Clonidine

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.

Clonidine: A quick overview

• Must never be stopped suddenly without consulting your care team
• Used primarily in people with hyperadrenergic PoTS
• Reduces excessive “fight-or-flight” nervous system activity
• Taken 2-3 times daily as a tablet or as a long-acting transdermal patch
• Acts faster than methyldopa
• Can cause significant drowsiness, fatigue, and brain fog
• Usually prescribed and monitored by a specialist

What is Clonidine?

Clonidine 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, Clonidine can reduce symptoms when standing for some people.

Who is usually prescribed Clonidine?

Clonidine 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

What does “off-licence” mean for me?

 Clonidine is officially licensed in the UK for the treatment of:

• High blood pressure (hypertension).
• Recurrent migraines
• Menopausal symptoms

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 its use in PoTS
• The healthcare professional takes on added responsibility compared to prescribing licensed medication
• A healthcare professional is responsible for monitoring your response

How does Clonidine help with PoTS symptoms:

Clonidine reduces sympathetic (“fight-or-flight”) signals from the brain.

This can:

• Relax blood vessels
• Lower blood pressure
• Reduce adrenaline-driven symptoms
• Increase blood plasma volume

Compared to methyldopa, clonidine is normally less well tolerated by people with PoTS since it:

• Acts faster
• Has a shorter duration

This can cause noticeable “peaks and troughs”, worsening side effects.

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?

Clonidine is typically taken as:

• Tablets (usually 0.1-0.2 mg, 2-3 times daily) or
• A long-acting transdermal patch.

Always take Clonidine exactly as directed by your doctor, dosing may vary depending on your individual situation.

Who should not take Clonidine?

Clonidine must be used under medical guidance and may not be suitable for those with:

• Low blood pressure
• Severe bradyarrhythmia (slow heart rate) or heart block
• A history of mental depression
• Constipation
• Kidney disease
• Raynaud’s syndrome or other occlusive peripheral vascular disease

Pregnancy and breastfeeding:

• Clonidine can affect foetal heart rate
• It passes into breast milk

Always discuss risks and benefits with your doctor.

Medical interactions:

Always inform your care team of other medications, especially medicines like:

• Monoamine oxidase inhibitors (MAOIs) (e.g., Isocarboxazid, Phenelzine)
• Beta-blockers (e.g., Bisoprolol, Atenolol)
• Central Nervous System (CNS) Depressants, like antihistamines, sedatives, or pain narcotics
• Tricyclic Antidepressants (e.g., Amitriptyline)

What are the side effects of Clonidine?

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
• Sexual dysfunction or decreased sexual ability

Other possible side effects include:

• Mental depression
• Anxiety
• Vivid dreams or nightmares
• Hives or swelling of the face, lips, or tongue (allergic reaction)

Seek urgent medical help if you experience severe sides effects or allergic reactions

How do I get and store Clonidine?

• Clonidine 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

A clinical report on Pharmacotherapy for postural tachycardia syndrome
https://www.autonomicneuroscience.com/action/showPdf?pii=S1566-0702%2818%2930025-0

Everything you need to know on Clonidine
https://www.mayoclinic.org/drugs-supplements/clonidine-oral-route/description/drg-20063252#drug-before-using
https://bnf.nice.org.uk/drugs/clonidine-hydrochloride/

A clinical review of the long-term side effects of taking Clonidine https://journal.chestnet.org/article/S0012-3692(15)40063-7/fulltext