Can you take Straterra (atomoxetine) with Buspar (buspirone)?

Can You Take Strattera (Atomoxetine) with Buspar (Buspirone)?

Yes, you can take Strattera (atomoxetine) with Buspar (buspirone), but this combination requires careful monitoring for serotonin syndrome and dose adjustments, particularly when initiating therapy. 1

Key Safety Considerations

Rifamycin Interaction with Buspirone

• Rifamycins (rifampin, rifabutin, rifapentine) substantially decrease buspirone concentrations, requiring clinical monitoring and potential dose increases or switching to alternative psychotropic medications. 1
• This interaction is clinically significant because rifamycins induce hepatic metabolism, reducing buspirone effectiveness. 1

Serotonin Syndrome Risk

• When combining atomoxetine with any serotonergic medication, monitor closely for serotonin syndrome within 24-48 hours of initiation or dose changes. 1
• Serotonin syndrome symptoms include mental status changes (confusion, agitation, anxiety), neuromuscular hyperactivity (tremors, clonus, hyperreflexia, muscle rigidity), and autonomic hyperactivity (hypertension, tachycardia, diaphoresis). 1
• Advanced symptoms can progress to fever, seizures, arrhythmias, and unconsciousness, potentially leading to fatalities. 1

Dosing Strategy for Combination Therapy

• Start atomoxetine at 40 mg daily when adding to existing buspirone therapy. 2
• Titrate atomoxetine every 7-14 days (to 60 mg, then 80 mg if needed), with maximum dose of 1.4 mg/kg/day or 100 mg/day, whichever is less. 2
• Increase doses slowly in the smallest available increments to minimize risk of behavioral activation and serotonin syndrome. 1, 3

Monitoring Requirements

Initial Assessment (First 24-48 Hours)

• Assess for early serotonin syndrome signs: agitation, tremor, confusion, myoclonus, diaphoresis. 4
• Monitor blood pressure and heart rate at baseline, 1 week post-initiation, and with each dose adjustment. 4

Ongoing Monitoring

• Monitor for suicidality, clinical worsening, and unusual behavioral changes, especially during the first few months or with dose changes. 3
• Watch for behavioral activation (motor/mental restlessness, insomnia, impulsiveness, disinhibited behavior, aggression), which can occur early in treatment or with dose increases. 3

Common Adverse Effects

Atomoxetine-Specific

• Nausea, vomiting, fatigue, decreased appetite, abdominal pain, somnolence. 3, 5
• Cardiovascular effects: slight increases in heart rate and blood pressure (statistically but not clinically significant in most cases). 5

Buspirone-Specific

• Headaches, dizziness, nervousness, lightheadedness. 6
• Buspirone has minimal sedation, no anticonvulsant or muscle-relaxant properties, and no abuse potential. 6

Contraindications for This Combination

Absolute Contraindications

• Current MAOI use or within 14 days of MAOI discontinuation (both medications). 2
• Active seizure disorder or history of seizures (particularly relevant if considering bupropion as alternative). 2
• Anorexia nervosa or bulimia nervosa (if bupropion considered). 2

Relative Contraindications

• Brain metastases (seizure risk with atomoxetine). 1
• Pregnancy and breastfeeding require careful risk-benefit discussion. 2

Clinical Pearls

Timing Expectations

• Atomoxetine requires 6-12 weeks to achieve full therapeutic effect, unlike stimulants which work within hours. 3
• Set appropriate expectations with patients about this delayed response timeline. 3

Drug Interactions

• CYP2D6 inhibitors (like paroxetine) increase atomoxetine exposure, requiring dose adjustments. 5
• Poor CYP2D6 metabolizers have greater atomoxetine exposure and slower elimination. 5

Emergency Management

• If serotonin syndrome develops, immediately discontinue both medications and provide hospital-based care with continuous cardiac monitoring. 4

Evidence Quality Note

The combination of atomoxetine and buspirone specifically has limited direct evidence. 7 The primary guideline addressing this combination focuses on monitoring for serotonin syndrome when combining serotonergic agents. 1 The rifamycin-buspirone interaction is well-established in tuberculosis treatment guidelines. 1