Atomoxetine

Sounds like 'at-oh-mox-e-teen'

Key points about atomoxetine

  • Atomoxetine is used to treat attention deficit hyperactivity disorder (ADHD).
  • The dose of atomoxetine will be different for different people.
  • Find out how to take it safely and possible side effects.
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Atomoxetine is used to treat attention deficit hyperactivity disorder (ADHD). It helps people with ADHD to concentrate better, be less impulsive and feel calmer. Atomoxetine works by increasing the amount of a natural chemical called noradrenaline (norepinephrine) in the brain and in this way increases attention and decreases hyperactivity in people with ADHD.

In Aotearoa New Zealand atomoxetine is available as capsules and comes in different strengths: 10mg, 18mg, 25mg, 40mg, 60mg, 80mg and 100mg.

  • The dose of atomoxetine will be different for different people, depending on your body weight and your response to the medication.
  • Always take your atomoxetine exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much atomoxetine to take, how often to take it, and any special instructions.

  • Take atomoxetine once or twice a day: Atomoxetine is usually taken once a day, in the morning. Sometimes, your doctor may recommend dividing the dose into 2, taking the first part of the dose in the morning and the other part late afternoon or early evening. Take your medicine at about the same time each day.
  • Swallow the capsules whole with a full glass of water: You can take your dose with or without food.
  • Keep taking atomoxetine regularly: Atomoxetine doesn't work straight away. It may take a few weeks before you notice some change in your symptoms. It's important to keep taking your medicine even if you feel well. From time to time your doctor will assess the treatment to make sure it's still required. This may involve stopping atomoxetine for a short while.
  • Missed dose: If you forget to take your dose, take it as soon as you remember. But if it is nearly time for your next dose, just take it at the right time. Don't take double the dose.

Here are some things to know when you're taking atomoxetine. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Check the strength of your capsules. Each time you collect a supply of atomoxetine, check that the capsules are the strength that you're expecting. There are several strengths of atomoxetine capsule. You will be given a strength that fits with your doctor's recommendations. If you are unsure about the dose and strength of capsule you are taking, talk to your pharmacist. Your dose may change over time.     
  • Atomoxetine and other medicines or supplements: Atomoxetine can interact with some medications, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting atomoxetine and before starting any new products.

Like all medicines, atomoxetine  can cause unwanted side effects, although not everyone gets them. Often unwanted side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Tummy upset
  • Nausea (feeling sick)
  • Headache
  • Reduced appetite 
  • These are quite common when you first start atomoxetine.
  • If you have nausea or a tummy upset, try taking your dose with food.  
  • Tell your doctor if these side effects bother you.
  • Feeling sleepy or drowsy
  • These are quite common when you first start atomoxetine.
  • Be careful when driving or using tools until you know how this medicine affects you.
  • Avoid drinking alcohol. Read more about how alcohol affects medicines.
  • Trouble sleeping 
  • Sleep problems are common when taking atomoxetine.
  • It's best to take your dose in the morning. If you are taking more than 1 dose per day, the second dose needs to be taken by early afternoon. Taking your dose too late in the day may keep you awake at night.
  • Tell your doctor if this bothers you.
  • Anxiety
  • Nervousness
  • Irritability 
  • Changes in mood


  • These are common when you first start atomoxetine.
  • Tell your doctor.
  • Prolonged erection (longer than 4 hours)
  • Tell your doctor immediately or ring Healthline 0800 611 116.
  • Suicidal feelings or behaviour such as agitation, aggression, self-harm, worsening of low mood.
  • These are rare but serious side effects.
  • These are most likely during the start of treatment of when doses are changed.
  • Contact your doctor immediately.
  • For urgent help contact Healthline 0800 611 116 or Lifeline 0800 543 354 (available 24/7).
  • Signs of problems with your liver such as severe tummy pain, yellowing of the eyes and skin, dark urine.
  • Atomoxetine can rarely cause liver problems.
  • Tell your doctor immediately or ring Healthline 0800 611 116
For more information on side effects, see the Medsafe consumer information leaflet/s below.

Did you know that you can report a medicine side effect to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.(external link)

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Credits: Sandra Ponen, Healthify pharmacist. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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