What are the side effects of Strattera (Atomoxetine)?

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Last updated: May 13, 2025View editorial policy

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From the Guidelines

Strattera (atomoxetine) can cause several side effects, including common ones like nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence, as well as more serious ones like increased risk of suicidal thoughts, particularly in children and adolescents, as noted in the study by 1.

Common Side Effects

  • Decreased appetite
  • Nausea
  • Vomiting
  • Fatigue
  • Abdominal pain
  • Somnolence These side effects are often mild and may diminish after the first few weeks of treatment as the body adjusts to the medication, according to 1.

Serious Side Effects

  • Increased risk of suicidal thoughts, particularly in children and adolescents, which has led to a black box warning by federal agencies and regulatory bodies, as stated in 1
  • Liver problems, indicated by yellowing of skin or eyes
  • Urinary retention
  • Priapism, a painful, prolonged erection
  • Mood changes, including increased suicidal thoughts, particularly when first starting the medication It is essential to monitor patients closely for these side effects, especially during the first few months of treatment or at times of dose change, as recommended in 1.

Growth and Development

Children taking Strattera might experience slower growth rates, and their height and weight should be monitored regularly, as noted in 1 and 1.

Cardiovascular Effects

Strattera may increase blood pressure and heart rate, although these effects are typically mild and clinically insignificant, as stated in 1.

Other Considerations

  • Strattera is primarily metabolized through the cytochrome P450 2D6 (CYP2D6) pathway, which should be taken into account when administering the medication, as noted in 1
  • Seven percent of the population are estimated to be poor metabolizers of atomoxetine, which may lead to increased adverse effects, as stated in 1 Overall, it is crucial to weigh the potential benefits of Strattera against its potential side effects and to closely monitor patients, especially children and adolescents, for any adverse reactions, as recommended in 1, 1, and 1.

From the FDA Drug Label

The most commonly observed adverse reactions in patients treated with atomoxetine hydrochloride (incidence of 5% or greater and at least twice the incidence in placebo patients, for either BID or QD dosing) were: nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence. Commonly observed adverse reactions associated with the use of atomoxetine hydrochloride (incidence of 2% or greater) and not observed at an equivalent incidence among placebo-treated patients (atomoxetine hydrochloride incidence greater than placebo) are listed in Table 2 The most commonly observed adverse reactions in patients treated with atomoxetine hydrochloride (incidence of 5% or greater and at least twice the incidence in placebo patients) were: constipation, dry mouth, nausea, decreased appetite, dizziness, erectile dysfunction, and urinary hesitation.

Side effects of Straterra (atomoxetine) include:

  • Gastrointestinal disorders:
    • Nausea
    • Vomiting
    • Abdominal pain
    • Constipation
  • General disorders:
    • Fatigue
    • Somnolence
  • Psychiatric disorders:
    • Mood swings
    • Insomnia
    • Depression
  • Nervous system disorders:
    • Headache
    • Dizziness
  • Renal and urinary disorders:
    • Urinary hesitation
    • Urinary retention
  • Reproductive system and breast disorders:
    • Erectile dysfunction
    • Ejaculation delayed and/or ejaculation disorder
  • Skin and subcutaneous tissue disorders:
    • Rash
    • Hyperhidrosis
  • Vascular disorders:
    • Hot flush

These side effects were reported in clinical trials with atomoxetine hydrochloride 2 and 2.

From the Research

Side Effects of Strattera

  • Common adverse events included:
    • Headache 3
    • Abdominal pain 3
    • Decreased appetite 3, 4
    • Vomiting 3
    • Somnolence 3
    • Nausea 3, 4
    • Dry mouth 4
    • Insomnia 4, 5
    • Constipation 4
    • Dizziness 4
    • Sweating 4
    • Dysuria 4
    • Sexual problems 4
    • Palpitations 4, 6
  • Less common side effects:
    • Irritability 6
    • Appetite reduction 6
    • Headache 6
  • Rare but serious side effects:
    • Suicidal ideation 3
    • Serious liver injury 3

Comparison of Side Effects with Other Medications

  • Strattera was found to have a lower risk of adverse events compared to methylphenidate in some studies 5
  • However, Strattera was associated with a higher risk of somnolence and lower risk of insomnia compared to methylphenidate 5

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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