Like all medicines, methylphenidate can cause side effects, although not everyone gets them.
Common side effects of methylphenidate for children
These common side effects of methylphenidate may happen in more than 1 in 100 children. There are things you can do for your child to help them cope with them:
Headaches
Make sure your child rests and drinks plenty of fluids. Painkillers such as paracetamol (Calpol) can help.
Talk to your doctor if your child's headaches are severe or do not go away.
Trouble sleeping (insomnia)
If your child is finding it hard to sleep, try giving them their last dose at least 6 hours before bedtime. Speak to their doctor if this does not help. They may want to try slow release tablets or capsules instead.
Loss of appetite
It may help to give your child methylphenidate with a meal.
You may notice they lose some weight during the first few months of treatment. Your child will probably put this weight back on once they are used to the medicine.
If you notice they are losing a lot of weight speak to their doctor.
Stomach ache
Try to get your child to rest and relax. It can help if they eat and drink slowly and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on their stomach may also help.
If they're in a lot of pain, or it does not go away, speak to a pharmacist or their doctor.
Dry mouth
This usually gets better quite quickly. It may help to give your child small sips of water and citrus fruits like oranges or satsumas.
Feeling or being sick
Stick to simple meals and do not give your child rich or spicy food if they feel sick. It might help to give them their methylphenidate with or after a meal or snack.
If they're being sick, encourage them to take small, frequent sips of water or squash to avoid dehydration.
If your child keeps being sick or having severe stomach pains, see a doctor.
Keep giving your child the medicine, but tell your child's doctor if the advice on how to cope does not help and these side effects bother your child or do not go away.
Serious side effects
Serious side effects are uncommon and happen in less than 1 in 100 people.
Methylphenidate can cause a small increase in blood pressure and pulse rate. A doctor will usually measure your child's blood pressure and pulse every 6 months.
Call your child's doctor or call 111 straight away if your child:
- has changes in mood or personality, for example, they start to behave aggressively, or they become irritable, depressed, anxious or tense
- has a fast or irregular heartbeat (palpitations) – your child may feel their heart is beating much faster than normal or may say it's racing
- starts seeing, feeling or hearing things that are not real (hallucinations)
- has started to get facial tics (quick, little movements in the the face muscles that cannot be controlled) – if this happens, their doctor may stop treatment
Immediate action required: Call 999 or go to A&E if your child starts having:
- thoughts about harming themself
- chest pains
- fits or seizures
- symptoms of a stroke, such as drooping on one side of the face, weakness on one side of the body, and slurring their words
Serious allergic reaction
It's possible for children to have a serious allergic reaction (anaphylaxis) to methylphenidate.
Immediate action required: Call 999 now if:
- your child's lips, mouth, throat or tongue suddenly become swollen
- they're breathing very fast or struggling to breathe (they may become very wheezy or seem like they're choking or gasping for air)
- their throat feels tight or they're struggling to swallow
- their skin, tongue or lips turn blue, grey or pale (if they have black or brown skin, this may be easier to see on the palms of their hands or soles of their feet)
- they suddenly become very confused, drowsy or dizzy
- they faint and cannot be woken up
- they're limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)
Your child may also have a rash that's swollen, raised, itchy, blistered or peeling.
These can be signs of a serious allergic reaction and may need immediate treatment in hospital.
Long-term side effects
If your child takes methylphenidate for longer than a year, it can slow down their growth. However, this happens in less than 1 in 10 children.
Your doctor will check your child's height, weight and appetite every 6 months to make sure they're growing OK.
Other side effects
These are not all the side effects of methylphenidate for children. For a full list, see the leaflet inside the medicine packet.
Reporting side effects
You can report any suspected side effect using the Yellow Card safety scheme.
Visit the Yellow Card website for more information about reporting side effects.