Common questions about methylphenidate for adults - Brand names: Ritalin, Concerta, Delmosart, Equasym, Medikinet

Methylphenidate is thought to work by boosting the levels of chemicals called dopamine and noradrenaline in your brain. This can increase activity in the parts of the brain that control attention and behaviour.

When you first take methylphenidate, you'll start on a low dose. Your doctor will usually increase this gradually until you find the dose that works best for you.

This means it might take a few weeks before you feel the full effect.

When you have found the right dose, methylphenidate should start to work within 30 to 60 minutes of taking it. How quickly it works depends on whether it's a standard or slow release tablet or capsule.

There's no evidence that methylphenidate is harmful if you take it exactly as prescribed. You'll have check-ups with your doctor every 12 months to see if you still need to take it.

You're unlikely to have any problems if you follow your doctor's instructions when taking methylphenidate.

The risk may increase, however, if you do not take methylphenidate properly. This includes taking it more often than your prescription says, or at a higher dose.

If you become physically dependent on methylphenidate, you're more likely to get withdrawal symptoms if you stop taking it suddenly.

Always follow the instructions carefully, and do not stop taking your medicine suddenly. Talk to your doctor first.

Only stop taking methylphenidate if your doctor tells you to. If you suddenly stop taking it, you may get withdrawal symptoms, such as depression.

Talk to your doctor if you want to stop taking methylphenidate. They may want to slowly reduce the amount you're taking, before you stop completely. This is to help you avoid any extra side effects.

Once you're on a brand of methylphenidate that works for you, you'll usually keep taking the same brand. Changing brands can cause problems, particularly if you're taking slow release tablets or capsules. This is because:

• different brands of slow release methylphenidate tablets and capsules release the medicine into your body in different ways, so this can affect how they work to manage your symptoms
• side effects for different brands can be different
• the instructions on how and when to take your medicine, such as whether to take it with food, will be different for each brand

If you do need to change brands, check the instructions that come with your medicine carefully.

Some people find that methylphenidate does not work for them. If this applies to you, your doctor may recommend other ADHD medicines, such as dexamfetamine, lisdexamfetamine or atomoxetine.

Psychological treatments for ADHD can also be helpful for some people. This includes behavioural therapy and talking therapy. Speak to your doctor if you are interested in finding out about alternative treatments.

Do not stop taking your methylphenidate without talking to your doctor first.

Some studies have suggested that supplements of omega-3 and omega-6 fatty acids can help people with ADHD. However, the evidence is very limited and more research is needed.

Talk to your doctor before taking any supplements.

Methylphenidate will not affect any type of contraception, including the combined pill, progestogen-only pill and emergency contraception.

But if methylphenidate makes you sick (vomit), your contraceptive pills may not protect you from pregnancy. Check the pill packet to find out what to do.

Find out more:

• What to do if you're sick when taking the combined pill
• What to do if you're sick when taking the progestogen-only pill

Some people might get side effects like feeling dizzy, blurred vision, difficulty focusing or feeling sleepy when taking methylphenidate. If this happens it may be dangerous to drive or ride a bike.

It's best not to drive, ride a bike, use heavy tools or machinery, or play sports until you know how methylphenidate affects you.

It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.

Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking methylphenidate.

GOV.UK has more information on the law on drugs and driving.

Try not to drink alcohol while taking methylphenidate. This is because alcohol can increase the effects of methylphenidate and make you more likely to get side effects.

Apart from alcohol, there's no particular food or drink you need to be careful with when taking methylphenidate.