Methylphenidate for adults: ADHD medicine explained

Methylphenidate is a stimulant. The NHS says it works by increasing activity in the brain, particularly in areas that help control attention and behaviour, by boosting dopamine and noradrenaline. In adults it is used to treat ADHD, and it is sometimes prescribed for narcolepsy.

Most adults can take it. Other ADHD medicines exist, including dexamfetamine, lisdexamfetamine and atomoxetine, and behavioural and talking therapies are also available.

Standard tablets are typically taken two or three times a day at least four hours apart, while slow-release tablets and capsules are usually taken once a day in the morning. Release mechanisms vary between brands, so the NHS says it is best to stay on the same brand once established, because changing can affect symptom control and side effects.

The NHS gives typical starting doses: 5 mg two to three times daily for standard tablets, 18 mg once daily for slow-release tablets, and 10 mg for slow-release capsules, adjusted gradually, often weekly. Your own dose will be set by your prescriber.

Swallow standard tablets whole with water, milk or squash. Slow-release tablets must not be crushed or broken. Some capsules can be opened onto soft food, but only if the brand allows it; check the leaflet. Timing varies by brand, so follow your label.

It can take several weeks to find the right type and dose, and once settled it works within 30 to 60 minutes. If you miss a dose, skip it and take the next at the usual time.

In an overdose, call 999 or go to A&E for seizures or an irregular heartbeat, and call NHS 111 for any overdose.

Common effects affect more than 1 in 100 people.

• Headaches: rest, fluids and paracetamol.

• Insomnia: take the last dose at least 6 hours before bed.

• Loss of appetite: take with meals; weight loss often reverses once you adjust.

• Stomach ache, dry mouth, nausea and vomiting.

• Call NHS 111 for mood or personality changes, a fast or irregular heartbeat, hallucinations or facial tics.

• Call 999 for self-harm thoughts, chest pain, stroke symptoms or seizures.

Tell the prescriber about swallowing difficulties, heart conditions, an overactive thyroid, an adrenal gland tumour (phaeochromocytoma), a personal or family mental health history, high blood pressure, epilepsy, tics or Tourette's syndrome in the family, glaucoma, and substance use disorders. Say if you are pregnant, trying to conceive or breastfeeding.

MAOI antidepressants must not be taken with methylphenidate, since they can cause a sudden dangerous rise in blood pressure. Check antidepressants, epilepsy medicines, blood pressure medicines, anticoagulants and some cough and cold remedies. Avoid alcohol, which amplifies effects. Avoid driving if you feel dizzy or have blurred vision or drowsiness.

Methylphenidate is not commonly used in pregnancy, and the decision depends on weighing benefits and risks with your doctor, midwife or pharmacist. Only minimal amounts pass into breast milk.

Treatment may last months or years but is not typically lifelong. Stop only after talking to your doctor, as reduction may be gradual to limit withdrawal such as low mood. It carries a low risk of addiction when taken as prescribed, which rises with misuse. Report suspected side effects to the MHRA Yellow Card scheme.