Atomoxetine (Strattera)

How does it work?

Strattera capsules contain the active ingredient atomoxetine hydrochloride, which is a type of medicine called a selective noradrenaline re-uptake inhibitor. It is a non-stimulant medicine used to treat attention deficit hyperactive disorder (ADHD).

Atomoxetine works in the brain, where it increases the levels of a natural chemical called noradrenaline. Noradrenaline is involved in passing messages between brain cells. Noradrenaline is considered to play an important role in regulating attention, impulsiveness and activity levels.

We don't fully understood how raising the levels of noradrenaline in the brain helps ADHD. However, the medicine has been shown to help control the symptoms of ADHD, and this may improve behaviour at school, self-esteem and family functioning.

Atomoxetine can be used to treat the symptoms of ADHD in children aged six years and over and adolescents. It will only be prescribed once a definite diagnosis of ADHD has been made, usually by a psychiatrist or a paediatrician specialising in ADHD. This specialist will also prescribe the medicine. It should be used as part of a comprehensive treatment programme involving behavioural therapy, psychotherapy, and educational techniques to help the child learn appropriate behaviour, as the medicine is not a cure in itself.

If the child is still taking the medicine after a year, it is recommended that they are re-evaluated by their ADHD specialist to make sure the medicine is still producing a beneficial effect.

What is it used for?

  • Attention deficit hyperactive disorder (ADHD) in children aged six years and over and adolescents.

In some cases it may be appropriate for adolescents to continue treatment into adulthood.

How do I take it?

  • Strattera is usually taken once a day in the morning. But if side effects are a problem, the dose can be split with one dose taken in the morning and one in the late afternoon/early evening. Follow the instructions given by your doctor.
  • Strattera capsules can be taken either with or without food.
  • The capsules should be swallowed whole with a drink. The capsules should not be opened because the powder inside is irritant to the eyes. If the powder inside the capsules accidentally comes into contact with the eye, the affected eye should be rinsed immediately with water and medical advice obtained. Hands and any potentially contaminated surfaces should be washed as soon as possible.
  • If you forget to take a dose you should take it as soon as you remember, unless it is nearly time for your next dose. In this case leave out the forgotten dose and just take your next dose as usual. Do not take a double dose to make up for a missed dose.


  • This medicine may cause sleepiness. If affected, potentially hazardous activities, such as riding bikes, climbing trees, driving or operating machinary should be avoided.
  • People taking this medicine should have their blood pressure and heart rate (pulse) checked before treatment is started. Blood pressure and pulse should then be regularly monitored (usually at least every six months and after any dose changes) for as long as the person is taking the medicine.
  • This medicine may decrease appetite and some children may lose weight during inital treatment. However, growth is not likely to be affected significantly. Your doctor will monitor height and weight as a precaution. If children are not growing or gaining weight as they should the doctor may suggest breaks from the medicine to allow growth to catch up.
  • Atomoxetine has been associated with causing or worsening some psychiatric disorders, such as depression, suicidal thoughts, hostility, anxiety, agitation, psychosis, hallucinations and mania. Children and adolescents taking this medicine should be monitored carefully and encouraged to report any new or worsening distressing feelings, thoughts about suicide or self-harm, depression, anxiety, agitation, irritability, mood changes, mood swings, anger, aggression, or any other unusual change in behaviour, thoughts or feelings that they may experience while taking the medicine. If you are worried about your child at any point, talk to your doctor immediately.
  • This medicine has very rarely been associated with liver problems. For this reason, people taking this medicine and parents of children taking this medicine should be aware of the symptoms of liver problems. These include unexplained itching, nausea and vomiting, right-sided abdominal pain, loss of appetite or flu-like symptoms; yellowing of the skin or eyes (jaundice), or unusually dark urine. Tell your doctor if any of these symptoms are experienced during treatment.
  • You should also tell your doctor or pharmacist if any other symptoms or side effects are experienced during treatment. Children on long-term treatment should be carefully monitored.

Use with caution in

  • Moderate to severely decreased liver function.
  • People with a poorly functioning enzyme in the liver called CYP2D6 (CYP2D6 poor metabolisers).
  • Kidney failure.
  • People with disease of the blood vessels in and around the brain (cerebrovascular disease).
  • People with disease involving the heart and blood vessels (cardiovascular disease).
  • People with an abnormality in the structure of the heart.
  • People with a faster than normal heart rate (tachycardia).
  • People with an abnormal heart rhythm seen on a heart monitoring trace (ECG) as a 'prolonged QT interval', or a family history of this, or who are taking other medicines that could increase the risk of this (see end of factsheet for examples).
  • High blood pressure (hypertension).
  • Low blood pressure (hypotension).
  • People with a history of depression or suicidal thoughts.
  • People with a history of psychotic or manic symptoms, eg hallucinations, delusional thinking or mania.
  • People with a history of seizures (fits), eg epilepsy.

Not to be used in

  • Children under six years of age.
  • Closed angle glaucoma.
  • People with a tumour of the adrenal glands (phaeochromocytoma) or a history of this.
  • People with a severe disorder affecting the blood vessels in the brain that could get worse if this medicine causes an increase in heart rate or blood pressure, for example an people with an aneurysm or stroke.
  • People with a severe disorder affecting the heart and blood vessels that could get worse if this medicine causes an increase in heart rate or blood pressure, for example people with very high blood pressure, heart failure, angina, an irregular heartbeat or other forms of heart disease.
  • People who have taken a monoamine oxidase inhibitor antidepressant (MAOI) in the last 14 days.

This medicine should not be used if your child is allergic to one or any of its ingredients. Please inform your doctor or pharmacist if your child has previously experienced such an allergy. If you feel your child has experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • The safety of this medicine for use during pregnancy has not been established. It is not recommended for use in pregnancy unless considered essential by your doctor, and only if the potential benefit to the mother outweighs any potential risks to the developing baby. Seek medical advice from your doctor.
  • If you are having sex it is important to use an effective method of contraception to avoid getting pregnant while you are taking this medicine. If think you could be pregnant or want to plan a pregnancy it is important to talk to your doctor straight away.
  • It is not known if this medicine passes into breast milk. For this reason it should be avoided during breastfeeding. Seek further medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that have been reported from clinical trials of this medicine in children and adolescents, and from reports following use of the medicine in children, adolescents and adults since the medicine has been on the market. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

Very common (affect more than 1 in 10 people)

  • Decreased appetite.
  • Headache.
  • Sleepiness.
  • Abdominal pain.
  • Feeling sick and vomiting.
  • Increase in blood pressure.
  • Increased heart rate (pulse).

Common (affect between 1 in 10 and 1 in 100 people)

  • Irritability or mood swings.
  • Difficulty sleeping (insomnia).
  • Dizziness.
  • Constipation.
  • Indigestion.
  • Rash or dermatitis.
  • Fatigue or lethargy.
  • Decreased weight.

Uncommon (affect between 1 in 100 and 1 in 1000 people)

  • Aggression or hostility.
  • Suicide-related events (see warning section above).
  • Waking early.
  • Dilated pupils.
  • Tremor.
  • Fainting.
  • Migraine.
  • Increased heart rate (pulse) or awareness of the heartbeat (palpitations).
  • Sweating or itching.

Unknown frequency (from reports since the medicine has been on the market)

  • Seizures.
  • Pins and needles or numb sensations.
  • Agitation, depression, anxiety and tics (see warning section above).
  • Psychosis, including hallucinations.
  • Cold hands and feet (Raynaud's phenomenon).
  • Liver problems (see warning section above).
  • Prolonged erection (priapism).
  • Male genital pain.
  • Difficulties passing urine.
  • Abnormal heart rhythm, seen as a 'prolonged QT interval' on a heart monitoring trace (ECG).

In clinical trials in adults, the most commonly reported side effects were decreased appetite, difficulty sleeping, dry mouth and feeling sick. Other side effects were similar to trials in children, except that adults also commonly reported sexual problems, such as difficulty getting or maintaining an erection, problems with ejaculation or orgasm, or problems with irregular or painful periods.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer. For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

You should tell your doctor what medicines your child is already taking before they start treatment with this medicine. This includes medicines bought without a prescription and herbal medicines. Likewise, once treatment has started you should always check with your doctor or pharmacist before using any new medicines. This is so they can check that the combination is safe.

This medicine must not be taken by people who are taking a type of medicine called a monoamine oxidase inhibitor (MAOI, for example phenelzine, tranylcypromine or isocarboxazid). It should also not be taken by people who have taken an MAOI medicine in the last 14 days.

Children who take salbutamol or other beta2agonists by nebuliser, injection, or as tablets to treat asthma, may find that their heart races when they take this medicine as well. This won't affect your child's asthma, but discuss it with your doctor if you are concerned. The medicine doesn't have this effect if salbutamol is taken by inhaler.

The manufacturer states that there may potentially be an increased chance of side effects if this medicine is taken in combination with other medicines that affect noradrenaline. These include the following:

  • antidepressants such as imipramine, venlafaxine, mirtazapine, reboxetine
  • the decongestants pseudoephedrine and phenylephrine. (These are found in several non-prescription cough and cold remedies, so always check with your pharmacist before giving these to children taking atomoxetine.)

There may be an increased risk of abnormal heart rhythms (prolonged QT interval on a heart monitoring trace (ECG) if atomoxetine is taken in combination with any of the following medicines:

  • medicines to treat abnormal heart rhythms (antiarrhythmics), eg amiodarone, procainamide, disopyramide, sotalol
  • certain antidepressants, eg fluoxetine, amitriptyline, imipramine, maprotiline, citalopram
  • certain antibiotics, eg clarithromycin, erythromycin, moxifloxacin
  • certain antifungals, eg ketoconazole, voriconazole
  • certain antimalarials, eg halofantrine, chloroquine, quinine, mefloquine, artemether
  • certain antipsychotics, eg thioridazine, chlorpromazine, pimozide, sertindole, haloperidol
  • cisapride
  • lithium
  • methadone
  • terfenadine
  • medicines that can alter the levels of salts such as potassium or magnesium in your blood, eg diuretics such as bendroflumethiazide or furosemide.

There may be an increased risk of seizures if atomoxetine is used in combination with the following medicines:

  • antidepressant medicines
  • antipsychotic medicines
  • bupropion
  • chloroquine
  • mefloquine
  • tramadol.

The following medicines may reduce the breakdown of atomoxetine by the liver and so could increase the level of atomoxetine in the blood:

  • fluoxetine
  • paroxetine
  • quinidine
  • terbinafine.

If any of these medicines are used in combination with atomoxetine, your doctor may need to adjust the dose of atomoxetine.

Atomoxetine may oppose the blood pressure lowering effect of medicines to treat high blood pressure (antihypertensives).

Other medicines containing the same active ingredient

There are currently no other medicines available in the UK that contain atomoxetine as the active ingredient.