Strattera (Atomoxetine) for ADHD with Comorbid Bipolar Disorder
Strattera can be used to treat ADHD in patients with comorbid bipolar disorder, but only after the bipolar disorder is first stabilized on a mood stabilizer regimen. 1
Critical Sequencing: Mood Stabilization Must Precede ADHD Treatment
- Stabilize bipolar symptoms first with a mood stabilizer (lithium, valproate, or atypical antipsychotic) before initiating any ADHD medication, as treating ADHD in the context of unstable mood symptoms can worsen bipolar disorder 1
- The mood stabilizer regimen needed to achieve acute stabilization should be maintained for 12-24 months minimum, as relapse rates exceed 90% in non-compliant patients 1
- Document adequate mood stability for at least 4-8 weeks before adding ADHD pharmacotherapy 1
Why Atomoxetine May Be Preferred in This Population
Atomoxetine has theoretical advantages over stimulants in bipolar patients because it lacks the mood-destabilizing potential associated with stimulant medications and carries no abuse liability. 2, 3
- Stimulants can precipitate manic episodes or worsen mood instability, though one controlled trial showed low-dose mixed amphetamine salts were safe when added to divalproex in stabilized bipolar youth 1
- Atomoxetine is not a controlled substance and has negligible abuse potential, making it particularly useful for patients at risk of substance abuse—a common comorbidity in bipolar disorder 2, 3, 4
- Atomoxetine may be beneficial for comorbid anxiety symptoms, which frequently co-occur with both ADHD and bipolar disorder 2, 4
Atomoxetine Dosing Protocol for This Population
Start atomoxetine at 40 mg orally once daily, then titrate every 7-14 days to 60 mg, then 80 mg, with a maximum dose of 100 mg/day or 1.4 mg/kg/day (whichever is less). 5, 6
- Begin with 40 mg once daily as the standard starting dose 5, 6
- Increase by 20 mg increments every 7-14 days based on tolerability and response 5
- Target dose is typically 80-100 mg daily for optimal efficacy 5, 6
- Allow 4-6 weeks at target dose to assess full therapeutic effect, as atomoxetine has a slower onset than stimulants 5, 2
Enhanced Monitoring Requirements
Patients with bipolar disorder require more intensive monitoring when adding atomoxetine, with systematic assessment for both ADHD symptom improvement and mood destabilization. 1, 6
- Monitor weekly during initial titration for mood symptoms (irritability, elevated mood, increased energy, decreased sleep need) that could signal emerging mania 1
- Screen systematically for suicidal ideation at each visit, as atomoxetine carries a black-box warning for increased suicidal thoughts in children and adolescents 6, 2
- Assess cardiovascular parameters (blood pressure, heart rate) at each adjustment, as atomoxetine causes modest increases that are generally well tolerated 1, 2
- Continue mood stabilizer monitoring (lithium levels, thyroid/renal function for lithium; liver function for valproate) per established protocols 1
Common Pitfalls to Avoid
- Never initiate atomoxetine during an acute mood episode (manic, hypomanic, or depressive), as ADHD treatment should only begin after mood stabilization 1
- Do not discontinue the mood stabilizer when adding atomoxetine; combination therapy is required, and monotherapy switches led to relapse in >50% of patients within 3 months 1
- Avoid underdosing atomoxetine—many patients require 80-100 mg daily for optimal effect, and stopping at 40 mg is inadequate 5
- Do not expect immediate results—atomoxetine requires 4-6 weeks at therapeutic doses for full efficacy, unlike stimulants which work immediately 5, 2
Alternative Consideration: Stimulants After Stabilization
If atomoxetine proves ineffective after an adequate trial (6-8 weeks at maximum tolerated dose), low-dose stimulants can be cautiously added to the mood stabilizer regimen, as demonstrated safe and effective in one randomized controlled trial of 40 bipolar youth stabilized on divalproex. 1