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Atomoxetine (Strattera®)

Atomoxetine (Strattera® and generics) is a non-stimulant medication used to treat ADHD.

What is this medication used for?

Health Canada has approved atomoxetine for use in children and adolescents age 6 years and older. It can help improve core symptoms of attention- deficit/hyperactivity disorder (ADHD), including difficulties paying attention, impulsive behaviour and hyperactivity.

Atomoxetine may also help reduce hyperactivity and impulsive behaviour associated with autism, and may be better tolerated than stimulants in children with anxiety or tic disorders. When potential benefits outweigh risks, atomoxetine may be prescribed “off-label.”Learn more about off-label medication use:

Tell your doctor or pharmacist if you:

  • Have allergies or bad reactions to a medication
  • Take (or plan to take) other prescription or
  • non-prescription medications, including natural medicines. Some medications interact with atomoxetine. Your doctor may adjust medication doses or monitor for side effects
  • Have a history (or family history) of kidney, liver or thyroid disease, high blood pressure or cholesterol, bipolar disorder, glaucoma or pheochromocytoma
  • Have a history (or family history) of heart disease, heart block, arrhythmia or “familial long QT syndrome”
  • Miss a period, are pregnant, breast-feeding or planning a pregnancy
  • Use alcohol or drugs. Taking atomoxetine together with certain substances may cause a bad reaction. Learn more at

When will the medication start to work?

You (or your family members) may notice some improvements in symptoms of ADHD after 3-4 weeks. However, full beneficial effects may take several months. Do not increase, decrease or stop taking atomoxetine if you do not notice improvements in the first 1-2 months as this delay in response is normal.

It is important that you continue taking atomoxetine regularly even if you are feeling well, as it can prevent symptoms from returning. Talk with your doctor if you feel atomoxetine treatment has not been helpful. Your doctor may recommend switching you to a different medication.

This medication is not addictive. Do not stop taking it before talking to your doctor.

How do I take this medication?

Atomoxetine is usually taken once or twice daily, with or without food, at the same time(s) each day. It needs to be taken regularly (every day) to be effective. Usually, you will start with a low dose and slowly increase this dose over several weeks, based on how you tolerate it.

Atomoxetine comes as capsules. They should be swallowed whole with fluid. They should not be opened, divided, crushed, chewed or placed in water.

Possible common or serious side effects:

Side effects may be more common when starting a medication or after a dose increase. Talk to your doctor, nurse or pharmacist if any side effect concerns you.

  • Headache
  • Drowsiness or fatigue
  • Difficulty sleeping
  • Dizziness or lightheadedness
  • High blood pressure or increased heart rate
  • An uncomfortable awareness of your heart beat
  • Nausea, vomiting or stomach ache
  • Decrease in appetite or weight gain

Contact your doctor immediately if you experience:

  • Thoughts of hurting yourself, hostility or suicide
  • Changes in mood to an unusual state of depression, excitement, irritability or happiness
  • Seeing, hearing or feeling things that are not there
  • Increased or worsened aggression, hostility or depression
  • Yellow or darkening skin, itching and abdominal pain
  • Prolonged (more than 4 hours), inappropriate and/or painful erection of the penis
  • Unexpected rash or seizure

What precautions should my doctor and I be aware of when taking this medication?

  • While taking atomoxetine, if you feel dizzy, drowsy or slowed down, do not drive a car or operate heavy machinery. Alcohol could make this worse. Try to avoid alcohol while taking atomoxetine.
  • Atomoxetine should not be used in combination with MAO inhibitors (linezolid, moclobemide, phenelzine and others) as they can interact. Symptoms include nausea, vomiting sweating, dizziness, tremors, severe muscle stiffness and increased agitation.
  • Atomoxetine can cause a temporary slowing of growth rate in children and adolescents in the first 9-12 months of treatment. This delay is usually less significant than growth delays associated with stimulant medications. It is also expected that the growth rate will catch up after about 3 years of treatment. However, some children may experience a more significant impact on growth. While taking atomoxetine, your growth should be monitored regularly.

How does this medication work?

Atomoxetine works by increasing levels of the brain chemical norepinephrine. Norepinephrine activates areas of the brain affecting impulsive actions, attention and body movements, thereby improving symptoms of ADHD and disruptive behaviours associated with autism.

What special instructions should I follow while using this medication?

  • Keep all your appointments with your doctor and the lab.
  • Your doctor may order physical exams, or assessments such ADHD rating scales and reports from your teachers, before or after starting atomoxetine. This is to make sure it is working well for you and monitor for side effects.
  • Do not allow anyone else to use your medication.

What should I do if I forget to take a dose of this medication?

If you forget to take a dose of atomoxetine, take the missed dose as soon as you remember. However, if it is more than 4 hours after your scheduled dose, skip the missed dose and continue with your regular schedule. DO NOT double your next dose to try to ‘catch up’.

How do I store this medication?

Keep this medication in the original container, stored at room temperature away from moisture and heat and protected from light. Keep this medication out of reach and sight of children.

How well does the medication work in children and adolescents?

Atomoxetine has been studied and found to improve core symptoms of ADHD (impulsive behaviour, inattention and hyperactivity) in approximately two-thirds of children and adolescents. Atomoxetine is often prescribed (alone or in addition to stimulants) when stimulants are not suitable or have not been effective or well-tolerated. It usually does not increase anxiety or tic severity, and may be better tolerated in children and adolescents who have ADHD and an anxiety or tic disorder. Limited evidence suggests that atomoxetine may also be effective for management of impulsive behaviour and hyperactivity problems associated with autism in children and adolescents. Whenever possible, the addition of behavioural management strategies (such as rewarding good behaviour and teaching problem-solving techniques) can increase the potential for benefit.

How long should I take the medication for?

This depends on the symptoms you have, how frequently they occur, and how long you have had them. Different people take atomoxetine for different lengths of time. From time to time, your doctor should evaluate whether you need ongoing treatment with this medication. Some people only require it during particular times of their life such as when they are in school. Other people benefit from ongoing treatment for many years.

Do not increase, decrease, or stop taking this medication without discussing it with your doctor. If you stop taking atomoxetine suddenly, it is possible that your symptoms may return gradually.

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