What is the recommended dose of atamoxetine (Strattera)?

From the Guidelines

The recommended dose of atomoxetine is 1.4 mg/kg/day or 100 mg/day, whichever is lower, with a sequential, weight-based approach for titration. When considering the treatment of ADHD with atomoxetine, it is crucial to weigh the benefits against the potential risks, including the increased risk of suicidal ideation in children and adolescents, as highlighted in analyses of twelve placebo-controlled trials 1. The dosing strategy typically involves starting with a lower dose and gradually increasing it, with the maximum recommended dosage being 1.4 mg/kg/day or 100 mg/day, whichever is lower, as specified by the manufacturer 1. Key considerations include:

• The patient's weight, as dosing is weight-based, especially for children and adolescents under 70 kg
• The potential for drug interactions, particularly with selective serotonin reuptake inhibitors that can elevate serum atomoxetine levels 1
• Close monitoring for suicidality, clinical worsening, and unusual changes in behavior, especially during the initial months of treatment or at times of dose change 1
• Awareness of common adverse effects such as nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence 1
• The presence of poor metabolizers, estimated to be around 7% of the population, who may experience significantly higher plasma levels and longer half-lives of atomoxetine, potentially leading to increased adverse effects 1.

From the FDA Drug Label

2 DOSAGE AND ADMINISTRATION

2.1 Acute Treatment Dosing of children and adolescents up to 70 kg body weight - Atomoxetine capsules should be initiated at a total daily dose of approximately 0.5 mg/kg and increased after a minimum of 3 days to a target total daily dose of approximately 1.2 mg/kg administered either as a single daily dose in the morning or as evenly divided doses in the morning and late afternoon/early evening. Dosing of children and adolescents over 70 kg body weight and adults - Atomoxetine capsules should be initiated at a total daily dose of 40 mg and increased after a minimum of 3 days to a target total daily dose of approximately 80 mg administered either as a single daily dose in the morning or as evenly divided doses in the morning and late afternoon/early evening After 2 to 4 additional weeks, the dose may be increased to a maximum of 100 mg in patients who have not achieved an optimal response.

The recommended dose of atomoxetine is:

• For children and adolescents up to 70 kg body weight:
  • Initial dose: 0.5 mg/kg/day
  • Target dose: 1.2 mg/kg/day
• For children and adolescents over 70 kg body weight and adults:
  • Initial dose: 40 mg/day
  • Target dose: 80 mg/day
  • Maximum dose: 100 mg/day 2

From the Research

Atomoxetine Dosing

• The typical dose of atomoxetine for adults with attention-deficit/hyperactivity disorder (ADHD) is 60-100 mg per day 3.
• A study found that patients were randomized to receive either 60-100 mg of atomoxetine or a placebo for 24 weeks, with a 2-week titration period 3.
• Another study analyzed real-world dosing patterns of atomoxetine in adults with ADHD and found that the mean dose was 68.5 mg/day, with 36.6% of patients being suboptimally dosed and 26.7% being treated at the recommended dose 4.

Titration and Dosing Strategies

• A slow titration strategy (40 mg for 7 days, then 80 mg) was compared to an on-label titration strategy (40 mg for 3 days, then 80 mg) in a study, with similar rates of adverse events but greater discontinuation due to adverse events in the on-label group 3.
• The study found that atomoxetine demonstrated significant improvement in ADHD symptoms at 12 and 24 weeks, regardless of the titration strategy used 3.

Safety and Efficacy

• Atomoxetine has been shown to be effective in reducing ADHD symptoms in adults, with significant improvements in Conners' Adult ADHD Rating Scale Total ADHD Symptoms score and Clinical Global Impression-ADHD-Severity 3, 5.
• However, atomoxetine has also been associated with adverse events such as dry mouth, nausea, and decreased appetite, as well as more serious events like hostility/aggression and cardiac disorders 6, 7.