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Clonidine Hydrochloride 100 microgram tablets – patient leaflet, side effects, dosage

Last updated: · Text from the MHRA, as of · About this document

Medicine status: Prescription only (POM) Details

Medicine strength:
100 microgram
Contains active substance:
ATC code:

Patient leaflet - Clonidine Hydrochloride 100 microgram tablets

1. What Clonidine 100 microgram Tablets are and what they are used for

Clonidine 100 microgram Tablets contain a medicine called clonidine. This belongs to a group of medicines called anti-hypertensives. Clonidine 100 microgram Tablets are used to lower high blood pressure (to treat hypertension).

2. What you need to know before you take Clonidine 100 microgram Tablets

Do not take Clonidine 100 microgram Tablets if:

  • You are pregnant, likely to get pregnant or are breast-feeding

  • You are allergic (hypersensitive) to clonidine or any of the other ingredients of Clonidine Hydrochloride Tablets (see section 6: Further information)
  • You have a slow heart rate due to heart problems Do not take this medicine if any of the above apply to you. If you are not sure, talk to your doctor or pharmacist before using Clonidine Hydrochloride Tablets.

Take special care with Clonidine 100 microgram Tablets

Check with your doctor or pharmacist before taking Clonidine 100 microgram Tablets if:

  • You have Raynaud's disease (a problem with circulation to the fingers and toes) or other blood circulation problems, including circulation to the brain
  • You have heart or kidney problems
  • You have or have ever had depression

•You have constipation

  • You have a nerve disorder that causes your hands and feet to feel different ('altered sensation') or low blood pressure when you stand up.

If you are not sure if any of the above apply to you, t talk to your doctor or pharmacist before taking Clonidine 100 microgram Tablets.

As you may get dry eyes whilst taking this medicine, this may be a problem if you wear contact lenses.

Taking other medicines

Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines. This includes medicines that you buy without a prescription and herbal medicines. This is because Clonidine Hydrochloride Tablets can affect the way some other medicines work. Also some other medicines can affect the way Clonidine 100 microgram Tablets work. In particular, tell your doctor or pharmacist if you are taking any of the following medicines:

  • Other medicines that make you drowsy • Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) such as ibuprofen
  • Medicines for depression such as imipramine or mirtazapine
  • Medicines for severe mental illness such as schizophrenia. These are also known as 'antipsychotics' and include chlorpromazine

    Please also tell your doctor or pharmacist if you are taking any of the following medicines for high blood pressure or other heart problems:

    • Beta blockers such as atenolol
    • Water tablets ('diuretics') such as furosemide
    • Alpha blockers such as prazosin or doxazosin. These can also be used for prostate problems in men • Vasodilators such as diazoxide or sodium nitroprusside
    • Calcium antagonists such as verapamil or diltiazem hydrochloride
    • ACE inhibitors such as captopril or lisinopril • Digitalis glycosides such as digoxin

If you are not sure if any of the above apply to you, talk to your doctor or pharmacist before taking Clonidine 100 microgram Tablets.

Tests

If you are having any blood tests, tell the person giving

the test that you are taking this medicine. This is because Clonidine 100 microgram Tablets can affect results relating to your liver.

You may feel drowsy while taking Clonidine Hydrochloride Tablets. Drinking alcohol while taking Clonidine 100 microgram Tablets can make this worse. Operations

If you are going to have an operation, keep taking your Clonidine 100 microgram Tablets. If you need to go into hospital, take the tablets with you.

Do not take Clonidine 100 microgram Tablets if you are pregnant, likely to get pregnant or are breast-feeding. Taking Clonidine 100 microgram Tablets with food and drink

You may feel drowsy, dizzy, or could have some disturbances of vision. If affected, you should not drive, operate machinery or take part in any activities where these may put you or others at risk. Pregnancy and breast-feeding

Driving or using machines

Important information about some of the ingredients of Clonidine 100 microgram Tablets

Clonidine 100 microgram Tablets contain lactose (a type of sugar). If you have been told by your doctor that you cannot tolerate or digest some sugars, talk to your doctor before taking this medicine.

This medicine contains less than 1 mmol sodium (23 mg) per tablets, that is to say essentially 'sodium-free'.

3. How to take Clonidine 100 microgram Tablets

Always take Clonidine 100 microgram Tablets exactly as your doctor has told you. You should check with your doctor or pharmacist if you are not sure.

Your doctor will start you on a low dose and gradually increase it. This will depend on how well your medicine works to control your blood pressure.

Taking this medicine

  • Take this medicine by mouth
  • The usual starting dose is between 50 microgram and 100 microgram, three times a day
  • If necessary, your doctor will gradually increase the dose
  • Most people's blood pressure is controlled by taking between 300 microgram and 1200 microgram Clonidine 100 microgram Tablets are not recommended for children.

If you take more Clonidine 100 microgram Tablets than you should

If you take more Clonidine 100 microgram Tablets than you should, talk to a doctor or go to a hospital straight away. Take the medicine pack with you, even if there are no tablets left.

If you forget to take 100 microgram Tablets

If you forget a dose, take it as soon as you remember it. However, if it is nearly time for the next dose, skip the missed dose. Do not take a double dose to make up for a forgotten dose.

If you stop taking Clonidine 100 microgram Tablets

Do not stop taking Clonidine 100 microgram Tablets without first talking to your doctor. If you have been using this medicine for a long time, you may feel agitated when you stop taking it. This is called a 'withdrawal effect'.

If you have any further questions on the use of Clonidine 100 microgram Tablets, ask your doctor or pharmacist.

4. Possible Side Effects

Like all medicines, Clonidine 100 microgram Tablets can cause side effects, although not everybody gets them.

The side effects described below have been experienced by people taking Clonidine Hydrochloride Tablets. They are listed as either very common, common, uncommon, rare or not known.

Very common (affects more than 1 in 10 people) • Dizziness, feeling tired and more relaxed than usual (sedation)

  • Feeling dizzy when you stand up (because your blood pressure has fallen sharply) Dry mouth

Common (affects less than in 1 in 10 people, more than 1 in 100 people)

  • Depression, sleeping problems
  • Headache
  • Constipation, feeling sick (nausea), pain below the ear (from the salivary gland), being sick (vomiting) • Erectile dysfunction
  • Fatigue

Uncommon (affects less than 1 in 100 people, more than 1 in 1,000 people)

  • Problems with understanding what is happening around you, hallucinations, nightmares
  • Your hands and feet feeling different ('altered sensation')
  • Regular unusually slow heart beat
  • Raynaud's phenomenon (a problem with circulation to the fingers and toes)
  • Itching, rash, urticaria (nettle rash)
  • A feeling of discomfort and fatigue ('malaise')

Rare (affects less than 1 in 1,000 people, more than 1 in 10,000 people)

  • Breast growth ('gynaecomastia') in men • Dry eyes
  • Irregular heartbeat
  • Drying out of the lining of the nose
  • Pseudo-obstruction of the large bowel, which causes colicky pain, vomiting and constipation. Contact your doctor straight away if you have all these side effects. • Hair loss
  • Increase in your blood sugar

Not known

  • Confusion, loss of libido
  • Blurred vision

•A bnormally slow heart beat

If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: www. mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side affects you can help provide more information on the safety of this medicine. Two cases of hepatitis (inflammation of the liver) have also been reported. This might show up in some blood tests. Your body may hold onto more water than usual (fluid retention).

Reporting of side effects

5. How to store Clonidine 100 microgram Tablets

Keep out of sight and reach of children.

Do not store above 30°C. Keep the blisters in the outer carton.

Do not use Clonidine 100 microgram Tablets after the expiry date which is stated on the packaging. The expiry date refers to the last day of that month. Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures will help protect the environment.

6. Contents of the pack and other information

What Clonidine 100 microgram Tablets contains • The active substance is clonidine hydrochloride. Each tablet contains 100 micrograms of clonidine hydrochloride.

  • The other ingredients are: lactose monohydrate, microcrystalline cellulose, maize starch, sodium starch glycolate Type-A , magnesium stearate, pregelatinised maize starch and povidone.

What Clonidine 100 microgram Tablets looks like and contents of the pack

White to off white, round shaped, biconvex uncoated tablet debossed with "C" separated by break line "100"

on one side and plain on other side. The tablets have diameter of 10.00 mm and thickness of 5.00 mm. The tablet can be divided into equal doses.

These medicines are available in Aluminium foil-PVC

White Opaque film blister packs of 100's tablets.

Marketing Authorization Holder

Flamingo Pharma (UK) Ltd.

First Floor, Kirkland House,

11-15 Peterborough Road,

Harrow, Middlesex,

HA1 2AX, United Kingdom.

Manufacturer

Flamingo Pharma (UK) Ltd.

The Bloc, 38 Springfield Way,

Anlaby, Hull, HU 10 6RJ,

United Kingdom

Clonidine Hydrochloride 100 microgram Tablets- PL 43461/0189

This leaflet was last revised in 04/2026.

MPLLCLO0100TB100 FPLXXX479V01_A

10 mm

5

About this document

Source: MHRA - Medicines and Healthcare products Regulatory Agency (products.mhra.gov.uk) · Marketing authorisation: PL 43461/0189

Last revision stated in the text: April 2026 · MHRA data as of 13 October 2026

Found a mistake? Tell us on the contact page.

The information on this site does not replace the advice of a doctor or pharmacist.

Facts about Clonidine Hydrochloride 100 microgram tablets

Prescription needed? Yes, prescription-only medicine (POM)
Active substance Clonidine
Strength 100 microgram
Pharmaceutical form Oral tablet
White to off white, round shaped, biconvex uncoated tablet debossed with “C” separated by break line “100”on one side and plain on other side. The tablets have diameter of 10.00 mm and thickness of 5.00 mm.
The tablet can be divided into equal doses.
How is it taken Oral
Excipients Lactose Monohydrate, Microcrystalline Cellulose, Maize Starch, Sodium Starch Glycolate Type-A, Magnesium Stearate, Pregelatinised maize starch, Povidone
Is it available? Listed as available (NHS Dictionary of Medicines and Devices – not a record of current supplies)
Shelf life 2 years
Storage Do not store above 30°C.
Keep the blisters in the outer carton.
Drug group (ATC) Antihypertensives
  1. C Cardiovascular system drugs
    1. C02 Antihypertensives
      1. C02A Antiadrenergic agents, centrally acting
        1. C02AC Imidazoline receptor agonists
          1. C02AC01 clonidine
Marketing authorisation PL 43461/0189 (first authorised 15 May 2026)
Marketing authorisation holder Flamingo Pharma (UK) Ltd.
Codes BNF 02050200

Sources: the MHRA product information (products.mhra.gov.uk) and the NHS Dictionary of Medicines and Devices (dm+d), release 10.1.0 of 12 October 2026, NHS Business Services Authority. Contains public sector information licensed under the Open Government Licence v3.0.