Patient Leaflet Updated 11-May-2026 | Neuraxpharm UK Ltd
Guanfacine prolonged-release tablets
Guanfacine 1 mg prolonged-release tablets
Guanfacine 2 mg prolonged-release tablets
Guanfacine 3 mg prolonged-release tablets
Guanfacine 4 mg prolonged-release tablets
Guanfacine 5 mg prolonged-release tablets
Guanfacine 6 mg prolonged-release tablets
Guanfacine 7 mg prolonged-release tablets
1. What Guanfacine is and what it is used for
2. What you need to know before you take Guanfacine
3. How to take Guanfacine
4. Possible side effects
5. How to store Guanfacine
6. Contents of the pack and other information
Guanfacine contains the active substance guanfacine. This medicine belongs to a group of medicines which affects brain activity. This medicine can help improve your attention, concentration and make you less impulsive and hyperactive.
This medicine is used to treat ‘attention deficit hyperactivity disorder’ (ADHD) in children and adolescents 6-17 years old for whom current stimulant medication is not appropriate and/or current medication does not adequately control ADHD symptoms.
The medicine is given as part of a treatment programme, which usually includes the following:
About ADHD
People with ADHD find it hard to:
ADHD can cause problems with everyday life. Children and young people with ADHD may have difficulty learning and doing homework. They can find it hard to behave well at home, at school or in other places.
Talk to your doctor or pharmacist before taking this medicine if:
Talk to your doctor or pharmacist if you are taking this medicine and:
Guanfacine may affect your weight and height if taking for long periods, your doctor will therefore monitor your growth.
Do not stop taking Guanfacine without talking to your doctor. If you suddenly stop taking Guanfacine, you may develop withdrawal symptoms of increased heart rate and high blood pressure (see section 4).
If any of the above apply to you (or you are not sure), talk to your doctor or pharmacist before taking this medicine. This is because this medicine can make these problems worse. Your doctor will routinely monitor you to see how this medicine affects you.
This medicine should not be used in children under 6 years of age and adults 18 years and over because it is not known if it works or is safe.
Before you start taking this medicine your doctor will check to make sure this medicine is safe for you and that it will help you. While you are taking this medicine your doctor will repeat these checks weekly during initial dosing, after dose adjustments, at least every 3 months for the first year and then at least twice a year. These checks may include:
You should talk to your doctor if you do not feel better or if you feel worse and very sleepy or drowsy after taking this medicine for around 6 weeks. Your doctor may want to review your treatment.
Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. This is because Guanfacine and some other medicines can affect each other.
In particular, tell your doctor or pharmacist if you are taking any of the following types of medicines:
Medicines Used to treat
Aprepitant Nausea and vertigo.
Atazanavir, efavirenz, etravirine, fosamprenavir, indinavir, nevirapine, ritonavir, saquinavir HIV infection.
Ciprofloxacin, chloramphenicol, clarithromycin, erythromycin, rifabutin, rifampicin, telithromycin Bacterial infections.
Fluconazole, itraconazole, posaconazole, ketoconazole Fungal infections.
Crizotinib, imatinib Cancer.
Diltiazem, verapamil Cardiovascular conditions.
Boceprevir, telaprevir Viral hepatitis.
Suboxone Substance dependence.
Bosentan Cardiovascular conditions (e.g. constriction of blood vessels in the lung).
Carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone Used to control epilepsy.
Modafinil Is a medicine that promotes alertness and is used to treat sleep disorders.
St. John’s Wort Is a herbal preparation that is used to treat depression.
If any of the above apply to you or you are not sure, talk to your doctor or pharmacist before taking this medicine.
If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.
You may feel dizzy and drowsy when taking this medicine, especially at the start of treatment and this may last for 2 to 3 weeks possibly longer. If this happens, do not drive, cycle, use any tools or machines or participate in activities that could cause injury until you know how this medicine affects you. Fainting has also been reported but is not a common effect.
Lactose is a type of sugar. If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicine.
This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially ‘sodium-free’.
Your treatment will start under the supervision of an appropriate specialist in childhood and/or adolescent behavioural disorders.
Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.
As part of your treatment your doctor will closely monitor how Guanfacine is affecting you during initial dosing and/or dose adjustments.
If you need to take Guanfacine for more than a year your doctor will monitor your response to treatment and your doctor may stop the medicine for a short time; this may happen during a school holiday. This will show if you still need to take the medicine.
If you take more Guanfacine than you should, talk to a doctor or go to a hospital straight away. Take the medicine pack with you and tell them how much you have taken.
The following effects may happen: low or high blood pressure, slow heart rate, slow breathing rate, feeling tired or exhausted.
If you forget a dose, wait until the next day and take your usual dose.
Do not stop taking this medicine without first talking to your doctor.
If you have any further questions on the use of this medicine, ask your doctor or pharmacist.
Like all medicines, this medicine can cause side effects, although not everybody gets them. If you are worried, speak to your doctor.
If you feel unwell in any way while you are taking your medicine please tell an adult straight away.
The following serious side effects have been reported: feeling drowsy (sedation), feeling dizzy (hypotension), slow heart beat (bradycardia), feeling faint or loss of conciousness (syncope), a serious withdrawal side effect of high blood pressure after suddenly stopping Guanfacine; symptoms may include headaches, feeling confused, nervousness, agitation, and tremors (hypertensive encephalopathy).
Some of these side effects are more likely to occur at the start of treatment and may disappear as you continue with your treatment, if you experience any of these side effects contact your doctor straight away.
The following side effects have been reported.
Very common (may affect more than 1 in 10 people)
Common (may affect up to 1 in 10 people)
Uncommon (may affect up to 1 in 100 people)
Rare (may affect up to 1 in 1,000 people)
Very rare (may affect up to 1 in 10,000 people)
Not known (frequency cannot be estimated from the available data)
If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
By reporting side effects you can help provide more information on the safety of this medicine.
Keep this medicine out of the sight and reach of children.
Do not use this medicine after the expiry date which is stated on the carton and blister pack after EXP. The expiry date refers to the last day of that month.
This medicinal product does not require any special storage conditions.
Do not use this medicine if the tablets or blister pack look damaged.
Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
The other ingredients are Hypromellose (2208), methacrylic acid-ethyl acrylate copolymer (Type A), lactose monohydrate, povidone K-30, crospovidone (Type A), microcrystalline cellulose, silica colloidal anhydrous, sodium laurilsulfate, polysorbate 80, fumaric acid, glycerol dibehenate.
Guanfacine is a prolonged-release tablet which means that the active substance is released from the tablet over a period of time. The tablets come in pack sizes of 28.
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This leaflet was last revised in March 2026
Neuraxpharm UK Ltd, Suite 2, Arlington Flex, Third Floor, Building 1420, Arlington Business Park, Theale, Reading, Berkshire, RG7 4SA, UK