Atomoxetine Side Effects and Considerations

Gastrointestinal and Administration Considerations

• Gastrointestinal symptoms, including decreased appetite, abdominal pain, nausea, and vomiting, are prominent side effects of atomoxetine, particularly if the dosage is increased too rapidly, affecting pediatric patients 1, 2
• Splitting the daily dose into morning and evening administration, or administering atomoxetine in the evening only, can help reduce these adverse effects 3

Cardiovascular and Monitoring Considerations

• Atomoxetine causes mild increases in heart rate and blood pressure, which are generally clinically insignificant, but regular monitoring of vital signs is recommended during treatment 1, 2
• Atomoxetine is associated with potentially clinically important changes in heart rate or blood pressure in 5-10% of pediatric patients 1, 2

Weight, Growth, and Metabolism Considerations

• Atomoxetine is linked to growth delays in the first 1-2 years of treatment, with return to expected measurements after 2-3 years on average, and has fewer appetite and growth problems compared to stimulants 1, 2, 3
• Poor CYP2D6 metabolizers experience significantly higher rates of adverse effects due to elevated plasma levels and longer half-lives 4

Safety and Discontinuation Considerations

• Atomoxetine carries an FDA black box warning for increased suicidal ideation in children and adolescents, requiring close monitoring especially during the first few months of treatment 1, 4
• Extremely rarely, hepatitis has been associated with atomoxetine, and treatment should be discontinued immediately if jaundice or clinically significant liver dysfunction develops 1, 2, 4