Atomoxetine is a medication primarily used to treat attention-deficit hyperactivity disorder (ADHD). It is associated with a range of common and serious side effects that patients and caregivers should monitor closely[1].
Common side effects of atomoxetine include:
- Nausea
- Vomiting
- Loss of appetite
- Weight loss
- Constipation
- Stomach pain or abdominal discomfort
- Dry mouth
- Excessive tiredness or feeling tired
- Dizziness
- Headache
- Mood swings
- Difficulty urinating
- Decreased sex drive or ability
- Painful or irregular menstrual periods
- Muscle pain
- Sweating
- Hot flashes
- Unusual dreams
- Burning or tingling sensations in the extremities (hands, arms, feet, or legs)
- Sleep changes, including insomnia
Many of these side effects are mild and may improve as the body adjusts to the medication[1][2][3][7].
Serious side effects that require immediate medical attention include:
- Fast or pounding heartbeat
- Chest pain
- Shortness of breath
- Slow or difficult speech
- Weakness or numbness of an arm or leg
- Itchy skin
- Dark urine
- Yellowing of skin or eyes (jaundice)
- Flu-like symptoms
- Pain in the upper right part of the stomach
- Swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
- Hoarseness
- Difficulty swallowing or breathing
- Hives
- Rash
- Abnormal thoughts or behavior
- Hallucinations (seeing or hearing things that are not real)
- Erection lasting several hours or longer (priapism)
- Seizures
Atomoxetine carries a boxed warning for increased risk of suicidal ideation in children and adolescents. Close monitoring is recommended, particularly when starting the medication or changing the dose[5][7].
Additional warnings include potential cardiovascular effects such as increased blood pressure and heart rate, as well as possible liver injury. Serious heart-related events—such as stroke and myocardial infarction—have been reported rarely. The medication may also slow growth or weight gain in children, so regular monitoring is advised[1][4].
If you experience any unusual or severe symptoms while taking atomoxetine, promptly consult your healthcare provider. This is not a complete list of side effects; consult prescribing information or your clinician for comprehensive details and individualized medical advice.