Can a patient take atogepant (oral calcitonin gene-related peptide receptor antagonist) if they are already on Aimovig (erenumab)?

Concurrent Use of Atogepant and Aimovig for Migraine Prevention

Yes, patients can take atogepant while on Aimovig (erenumab), as these medications work through complementary mechanisms targeting the CGRP pathway and there is no evidence of harmful interactions between them.

Mechanism of Action and Rationale

• Aimovig (erenumab): A monoclonal antibody that blocks the CGRP receptor
• Atogepant: An oral small-molecule CGRP receptor antagonist (gepant)

These medications work through different pharmacological approaches to target the same pathway:

• Erenumab binds to the CGRP receptor with high specificity and long duration
• Atogepant provides daily oral CGRP receptor blockade with different pharmacokinetics

Evidence Supporting Combination Therapy

The 2024 VA/DoD Clinical Practice Guideline for Headache Management strongly recommends CGRP monoclonal antibodies like erenumab for both episodic and chronic migraine prevention (strong for recommendation) 1. The same guideline gives atogepant a "weak for" recommendation for episodic migraine prevention 1.

Recent real-world evidence demonstrates that:

• Atogepant shows effectiveness in treatment-resistant chronic migraine patients, including those who previously failed CGRP monoclonal antibody therapy 2
• In a real-world study, 47% of patients who had failed prior CGRP monoclonal antibody therapy still achieved ≥50% reduction in monthly migraine days with atogepant 2

Clinical Decision Algorithm

1. Assess current response to Aimovig:

   • If patient has partial response (30-50% reduction in migraine days) but still has significant burden
   • If patient has breakthrough migraines despite Aimovig

2. Consider adding atogepant if:

   • Patient has episodic migraine (fewer than 15 headache days per month) 1
   • Patient has tried and failed multiple other preventive treatments 3
   • Patient desires additional migraine prevention beyond what Aimovig provides

3. Dosing recommendation:

   • Standard atogepant dose is 60mg once daily 3, 4
   • Continue Aimovig at its prescribed schedule (typically monthly injections)

Efficacy Expectations

When adding atogepant:

• Expect additional reduction in monthly migraine days (2.4 fewer days compared to placebo in treatment-resistant patients) 3
• Potential for improved response in patients with partial response to Aimovig
• Long-term studies show increasing benefit over time, with mean reduction of 5.2 migraine days by weeks 49-52 4

Safety Considerations

• Most common side effects of atogepant are constipation (7-10%) and nausea (6%) 3, 4
• No known dangerous drug interactions between atogepant and erenumab
• Monitor for:
  • Constipation (most common adverse effect with both medications)
  • Potential additive effects on liver function
  • Hypertension (particularly with erenumab) 1

Cost Considerations

The 2025 ACP guideline notes significant cost differences between medication classes 1:

• CGRP monoclonal antibodies and gepants are substantially more expensive ($7,071-$22,790 annually) compared to traditional preventives
• Consider cost implications when adding a second high-cost medication

Important Caveats

• While there are no specific contraindications to combining these medications, there is limited direct evidence on their concurrent use
• The 2025 ACP guideline suggests trying lower-cost alternatives before CGRP-targeting therapies due to similar efficacy but vastly different costs 1
• Patients generally prefer oral treatments over injectables when efficacy is similar 1

Follow-up Monitoring

• Assess response after 12 weeks (standard evaluation period in clinical trials) 3, 5
• Consider discontinuation if less than 30% reduction in headache parameters after 2-3 months 6
• Document headache frequency, duration, and severity at each visit to justify continued therapy 6