Guanfacine for ADHD

This leaflet is for parents and carers about how to use this medicine in children. Our information may differ from that provided by the manufacturers, because their information usually relates to adults. Read this leaflet carefully. Keep it somewhere safe so that you can read it again.

Do not suddenly stop giving Guanfacine without talking to your doctor first.

Name of medicine


Brand names: Intuniv

Why is it important for my child to take Guanfacine?

Guanfacine will help to reduce the symptoms of hyperactivity and impulse behaviour and increase attention and concentration span. It is used as part of a comprehensive treatment programme that includes behavioural therapy.

What is Guanfacine available as?

  • Modified release tablets: 1 mg, 2 mg, 3 mg, 4 mg contain lactose.

When should I give Guanfacine

Guanfacine is usually given once each day. This can be in the morning or the evening.

Give it at about the same time each day so that this becomes part of your child’s daily routine, which will help you to remember.

How much should I give?

Your doctor will work out the amount of medicine (the dose) that is right for your child. The dose will be shown on the medicine label.

Your doctor will probably start with a low dose and then increase it gradually to find the lowest dose that works for your child. Guanfacine can affect your child’s pulse and blood pressure so your doctor may need to check these before any changes can be made.

It is important that you follow your doctor’s instructions about how much to give.

How should I give Guanfacine?

Modified-release tablets

  • Modified-release tablets should be swallowed whole with a glass of water, juice, or squash. Your child should not chew the tablet because this will change how it works.

When should the medicine start working?

It may take 3-4 weeks for guanfacine to work properly so you may not see much difference in your child’s symptoms for the first few weeks. It is important that you continue to give the medicine as you have been told to by the doctor, nurse or pharmacist.

What if my child is sick (vomits)?

  • If your child is sick less than 30 minutes after having a dose of Guanfacine, give them the same dose again.
  • If your child is sick more than 30 minutes after having a dose of Guanfacine, do not give them another dose. Wait until the next normal dose.

If your child is sick again, seek advice from your family doctor, nurse, pharmacist, or hospital. They will decide what to do based on your child’s condition and the specific medicine involved.

What if I forget to give it?

If you usually give it once a day: Give the missed dose when you remember during the day, as long as this is at least 12 hours before the next dose is due.

If two or more consecutive doses are missed. Contact your child’s doctor as their dose may need to be slowly increased back up to the original dose.

Never give a double dose of Guanfacine.

What if I give too much?

If you think you may have given your child too much Guanfacine, contact your doctor or local NHS services (details at end of leaflet) or take your child to hospital. Have the medicine container or packaging with you, even if it is empty. This will be useful to the doctor.

Are there any possible side effects?

We use medicines to make our children better, but sometimes they have other effects that we don’t want (side effects).

Side effects you must do something about

If your child has an irregular or fast heart beat (they may say their heart feels fluttery or is racing), contact your doctor straight away.

Your child may become irritable, aggressive, tearful, depressed or anxious. These effects are temporary and reverse on stopping treatment. If you are worried contact your doctor as soon as possible.

Your child should not stop taking Guanfacine suddenly as this may affect their blood pressure.

Other side-effects you need to know about

  • When your child first starts taking guanfacine, they may have headaches, lose their appetite, feel sick (nausea) or be sick (vomit), have stomach pain and feel sleepy. These effects should wear off after 1-2 weeks as your child’s body gets used to the medicine.
  • Your child may lose or gain weight during the first few months of treatment. Contact your doctor if you are concerned.
  • Your child might seem irritable and have mood swings. Some children will get nightmares or see strange things (hallucinations). 
  • Your child might feel dizzy or light headed, especially when standing up. Encourage them to stand up slowly, and to sit or lie down if they feel dizzy or light headed.
  • They may be hungrier than usual (increased appetite). Encourage them to eat fruit and vegetables and low-calorie foods, rather than foods that contain a lot of calories (avoid crisps, cakes, biscuits and sweets), and to have plenty of exercise. Otherwise they may put on weight.


  • They may get a rash or swollen, reddened, itchy skin. Contact your doctor or pharmacist if this becomes troublesome.

  • Your child may feel tired or have difficulty sleeping.

  • Your child may have a dry mouth. Eating citrus fruits (e.g. oranges) and sipping water may help.

There may sometimes be other side effects that are not listed above. If you notice anything unusual and are concerned, contact your doctor. You can report any suspected side effects to a UK safety scheme at

Can other medicines be given at the same time as Guanfacine?

  • You can give your child medicines that contain paracetamol or ibuprofen, unless your doctor has told you not to.
  • Guanfacine should not be taken with some medicines. Tell your doctor or pharmacist about any other medicines your child is taking before giving Guanfacine.
  • Check with your doctor or pharmacist before giving any other medicines to your child. This includes herbal and complementary medicines.
  • Guanfacine may affect your child’s blood pressure. It is important to tell your doctor if they are taking any medicines to treat high blood pressure.

Is there anything else I need to know about this medicine?

Your child should not eat grapefruit or drink grapefruit juice as this may increase the amount of Guanfacine in the body, which could be harmful.

It is important for your child to have their height, weight, pulse and blood pressure checked regularly whilst taking Guanfacine. Your doctor will tell you how often.

  • Guanfacine can affect the ability to do skilled tasks such as riding a bicycle, playing sports or driving. Your child should take care when doing tasks that require co-ordination until they get used to the medicine.
  • Guanfacine may harm an unborn baby. If your daughter is sexually active, it is important that she uses adequate contraception to prevent pregnancy and continues it for at least 1 month after stopping Guanfacine.
  • The oral contraceptive pill can be used safely in women or girls taking Guanfacine.
  • If your daughter thinks she may be pregnant, she should see her doctor as soon as possible but continue taking Guanfacine in the meantime.

General advice about medicines

  • Try to give medicines at about the same times each day, to help you remember.
  • If you are not sure a medicine is working, contact your doctor but continue to give the medicine as usual in the meantime. Do not give extra doses, as you may do harm.
  • Only give this medicine to your child. Never give it to anyone else, even if their condition appears to be the same, as this could do harm.
  • If you think someone else may have taken the medicine by accident, contact your doctor for advice.
  • Make sure that you always have enough medicine. Order a new prescription at least 2 weeks before you will run out.
  • Make sure that the medicines you have at home have not reached the ‘best before’ or ‘use by’ date on the packaging. Give old medicines to your pharmacist to dispose of.

Where should I keep this medicine?

  • Keep the medicine in a cupboard, away from heat and direct sunlight.
  • It does not need to be kept in the fridge.
  • Make sure that children cannot see or reach the medicine.
  • Keep the medicine in the container it came in.

Who to contact for more information?

Your child’s doctor, pharmacist or nurse will be able to give you more information about Guanfacine and about other treatments for ADHD.

England: NHS 111

Tel 111

Scotland: NHS 24

Northern Ireland: NI Direct

Wales: NHS 111 Wales

ADDISS (ADHD Information Services)

020 8952 2800

Copyright disclaimer

Version [1]. © NPPG, RCPCH and WellChild, all rights reserved. Review by August 2024.

The primary source for the information in this leaflet is the British National Formulary for Children. For details on any other sources used for this leaflet, please contact us through our website,

We take great care to make sure that the information in this leaflet is correct and up-to-date. However, medicines can be used in different ways for different patients. It is important that you ask the advice of your doctor or pharmacist if you are not sure about something. This leaflet is about the use of these medicines in the UK, and may not apply to other countries. The Royal College of Paediatrics and Child Health (RCPCH), the Neonatal and Paediatric Pharmacists Group (NPPG), WellChild and the contributors and editors cannot be held responsible for the accuracy of information, omissions of information, or any actions that may be taken as a consequence of reading this leaflet.