From the Guidelines
The maximum recommended dose of atomoxetine is 1.4 mg/kg/day or 100 mg/day, whichever is lower. This dosage guideline is based on the most recent evidence from a 2022 study published in Pharmacology and Therapeutics 1.
Key Considerations
- Atomoxetine is orally administered and primarily metabolized through the cytochrome P450 2D6 (CYP2D6) pathway, which should be taken into account when considering potential drug interactions 1.
- The medication is available in capsules containing 10,18,25,40,60,80, or 100 mg of atomoxetine hydrochloride, as well as in an oral solution (4 mg/ml) 1.
- Titration follows a sequential, weight-based approach, and it is essential to monitor patients closely for suicidality, clinical worsening, and unusual changes of behavior, especially during the first few months of treatment or at times of dose change 1.
Important Side Effects and Warnings
- Common adverse effects of atomoxetine include nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence 1.
- Warnings exist for preexisting cardiovascular diseases/significant cardiac abnormalities, emergent psychotic or manic symptoms, bipolar disorder, aggressive behavior or hostility, possible allergic reactions, effects on urine outflow and growth, and priapism in children, adolescents, and adults 1.
Special Populations
- Approximately 7% of the population are poor metabolizers of atomoxetine, with significantly higher plasma levels and longer half-lives, which may lead to an increase in adverse effects 1.
From the FDA Drug Label
The maximum recommended atomoxetine hydrochloride dose was 2 mg/kg/day The maximum dose of atomoxetine is 2 mg/kg/day. 2
From the Research
Maximum Dose of Atomoxetine
- The maximum dose of atomoxetine is not explicitly stated in all studies, but according to 3, the recommended dosing of atomoxetine is weight-based, with a target dosage of 1.2 mg/kg/day in children and adolescents weighing 70 kg or less and 80 mg/day in children and adolescents weighing over 70 kg and adults.
- Study 4 mentions that despite the recommended 80 mg/day target dose, real-world data show that an approximately 60 mg/day average adult atomoxetine dose is utilized, suggesting that the maximum dose may not always be reached in practice.
- Study 5 used a dose range of 60-100 mg of atomoxetine in adults with attention-deficit/hyperactivity disorder, indicating that doses up to 100 mg may be used in some cases.
Dosage Considerations
- Atomoxetine dose titration, setting patient expectations, and the importance of keeping the patient at target dose for an adequate length of time (about 4−6 weeks) prior to judging efficacy are discussed in 4.
- The dosage and administration of atomoxetine may vary depending on individual patient needs and response to treatment, as noted in 3 and 5.