Can You Increase Strattera to 60mg While on Lexapro 10mg?
Yes, you can increase atomoxetine (Strattera) to 60 mg while on escitalopram (Lexapro) 10 mg, but you must use modified dosing due to a significant drug interaction—escitalopram inhibits CYP2D6 (though less potently than some other SSRIs), which can increase atomoxetine exposure and requires careful titration and monitoring. 1
Key Pharmacokinetic Consideration
Escitalopram has mild CYP2D6 inhibitory effects, which means it can increase atomoxetine plasma concentrations, though the interaction is less pronounced than with strong CYP2D6 inhibitors like sertraline or paroxetine. 1
The evidence base for atomoxetine co-prescription focuses primarily on sertraline (a moderate-to-strong CYP2D6 inhibitor), which causes a 6- to 8-fold increase in atomoxetine exposure. 1 While escitalopram's inhibition is weaker, caution is still warranted.
Recommended Dosing Strategy
For Adults (Your Patient's Likely Category)
Start atomoxetine at 40 mg/day when co-prescribed with an SSRI that has CYP2D6 inhibitory properties. 1
After a minimum of 3 days (preferably longer to assess tolerance), you may increase to 60 mg/day if symptoms persist and the medication is well-tolerated. 1
The maximum dose should not exceed 100 mg/day when combined with CYP2D6 inhibitors. 1
In clinical trials without CYP2D6 inhibitors, adults typically received 60-120 mg/day with a mean final dose of approximately 95 mg/day. 2
Critical Monitoring Requirements
Early Monitoring (First 24-48 Hours After Dose Change):
- Watch for serotonin syndrome, though the risk is lower than with MAOIs—look for mental status changes (confusion, agitation, anxiety), neuromuscular hyperactivity (tremor, clonus, hyperreflexia), and autonomic instability (hypertension, tachycardia, diaphoresis). 1
Cardiovascular Monitoring (Every Visit):
Measure heart rate and blood pressure at every clinical encounter, as atomoxetine causes modest elevations in both parameters. 1, 3
Obtain a detailed personal and family cardiac history before escalating doses. 1
Perform an ECG if cardiac risk factors are present. 1
Suicidality Monitoring:
Both atomoxetine and escitalopram carry black-box warnings for suicidal ideation, particularly in youth but also relevant in adults during the first months of treatment and after dose adjustments. 1, 3
Monitor closely for emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, impulsivity, or suicidal thoughts. 1
Behavioral Activation:
Agitation and behavioral activation are more common after dose escalations, especially when SSRIs are combined with atomoxetine. 1
Early somnolence and gastrointestinal symptoms (nausea, vomiting, decreased appetite, abdominal pain) are especially likely if the dose is increased rapidly. 1
Common Pitfalls to Avoid
Do not increase too rapidly—the guideline-based approach for CYP2D6 inhibitor combinations recommends waiting at least 3 days (preferably 4 weeks) before titrating upward. 1
Do not ignore cardiovascular contraindications—significant cardiovascular disease or long QT syndrome are relative or absolute contraindications to this combination. 1
Approximately 7% of the population are CYP2D6 poor metabolizers, resulting in higher plasma concentrations and greater adverse effects even without SSRI co-administration. 1 If your patient experiences excessive side effects at standard doses, consider genetic testing.
Safety Profile
The combination of atomoxetine with SSRIs has been studied in augmentation trials for depression, where atomoxetine 40-80 mg/day was safely added to ongoing SSRI therapy. 4, 5
In these studies, the most common side effects were activation, insomnia, increased anxiety, nausea, and dry mouth. 4, 5
No significant changes in heart rate or blood pressure were observed in augmentation studies, though systematic monitoring is still required. 4
Bottom Line
Proceed with the increase to 60 mg atomoxetine, but do so cautiously with close monitoring for serotonin syndrome, cardiovascular effects, suicidality, and behavioral activation during the first week after the dose change. 1, 3 The 60 mg dose is within the safe range for adults on concurrent SSRI therapy, provided you monitor appropriately and do not exceed 100 mg/day total. 1