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Atomoxetine - What is it for

Atomoxetine is used to treat attention deficit hyperactivity disorder (ADHD). It works by increasing the amount of a brain chemical substance called noradrenaline to increase attention, concentration and reduce impulsive and hyperactive behaviour.

Atomoxetine - Side Effects, Precautions, and Contraindications

What side effects can Atomoxetine cause?

Common side effects include:

  • Stomach discomfort e.g. stomach pain, nausea, vomiting
    • Take it after food to minimise these side effects
  • Dry mouth
  • Constipation
  • Decreased appetite and weight loss
  • Excessive sweating
  • Headache, difficulty in sleeping or drowsiness
  • Decrease in sexual drive or ability
Most of these side effects will get better or go away as your body gets used to the medication.

Inform your doctor if the side effects above become severe and bothersome.

Very rarely, this medication may cause

  • Fast or irrgular heartbeat (palpitations)
  • Very high blood pressure
    • Signs and symptoms may include severe headache or dizziness, fainting or change in eyesight
  • Liver problems
    • Signs and symptoms may include dark urine, feeling tired, loss of appetite, upset stomach or stomach pain, throwing up, light-coloured stools, yellow skin or eyes
  • Prolonged and/or painful erections (for males) lasting up to 4 hours or beyond
  • Trouble passing urine
  • New or worsening mental symptoms such as delusions (false beliefs), hallucinations (seeing or hearing things that are not real) or mania (abnormally high or excited mood)

The symptoms of a drug allergy include one or more of the following:

  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

Before taking Atomoxetine , what precautions must I follow?

Inform your healthcare professional if:

  • You are allergic to this medication or any of the other ingredients of this medication
  • You are pregnant, planning to become pregnant, or breastfeeding
  • You are taking any other medications, including supplements, traditional medications and herbal remedies currently or in the last two weeks.
  • You have a history of or current medical conditions such as blood vessel disease, high blood pressure, stroke, heart disease, pheochromocytoma (tumour in the adrenal glands), mental health conditions, glaucoma, overactive thyroid, liver disease, seizures (fits), hard-to-control or repeated twitching of any parts of the body or you repeat sounds and words (Tourette's syndrome or tics disorder)


In some cases, particularly in young people below the age of 25 years, this medication may cause the following changes to a person's mental condition, especially in the first few weeks of treatment or during dose changes:

  • New or worsening thoughts of harming yourself or ending your life
  • Worsening agitation, restlessness, violent behaviour, or
  • Other changes in mood or behaviour

Please inform your doctor as soon as possible, or for your family or caregiver to inform your doctor if you are unable to seek treatment on your own.

Do not stop taking this medication on your own without discussing with your doctor.

It is important to note that your doctor has prescribed this medication as he/she feels you will benefit more from taking this medication over the possible risks that it may cause, which have a low chance of occurring, and most people take this medication without any of such problems.

What food or medicine must I avoid when I take Atomoxetine ?

Some medications might interact with atomoxetine. Check with your doctor or pharmacist if you want to take/give any other medications, supplements or herbal products.

If you see another doctor, inform him that you are taking this medication before he prescribes any other medications.

Atomoxetine - Dosage and How to Use

How should Atomoxetine be used?

  • Do not stop taking your medication without checking with your healthcare professional.
  • You may take this medication with or without food.
  • Do not crush, chew or open up the capsules as the contents may irritate the eye. If the contents of the capsule come into contact with the eye, flush it immediately with water and seek medical advice. Wash your hands and any potentially contaminated surface as soon as possible.
  • Your doctor would start the medication at a low dose, and then slowly adjust the dose according to your response. It will take a few weeks for the medication to work properly, so you may not see a difference in your symptoms in the beginning. It is important that you continue to give the medication as you have been told by your doctor. The improvement in symptoms may also vary from person to person.

What should I do if I miss a dose?

If you forget to take a dose, take it as soon as you remember (but do not take more than your total daily dose prescribed in any 24 hours). Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What should I do if I overdose?

Atomoxetine - Handling

How should I handle Atomoxetine safely?

Atomoxetine - Storage

How should I store Atomoxetine ?

;#Keep away from children;#Keep in a cool, dry place, away from direct sunlight;#

How should I dispose of Atomoxetine safely?

​Pack this medication into a trash bag and seal it tightly before throwing into the rubbish chute or bin.

Atomoxetine - Additional Information

  • Updated on 7/31/2022 12:00:00 AM
  • Article contributed by PSS National Medication Information Workgroup PSS National Medication Information Workgroup
The information provided is not intended as medical advice. Terms of use. Information provided by SingHealth

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