CGRP antagonists vs traditional migraine prophylaxis (topiramate, propranolol, amitriptyline) — when to escalate?

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### Migraine Prophylaxis: Escalating to CGRP-Targeted Therapies **1. Escalation Criteria for CGRP Monoclonal Antibodies (mAbs)** The American Headache Society (AHS) 2024 position statement update suggests that CGRP mAbs (erenumab, fremanezumab, galcanezumab, and eptinezumab) can be considered as first-line or second-line preventive treatments. * **Traditional Criteria:** Most payers still require failure (inadequate response or intolerable side effects) of 2-3 traditional classes (e.g., topiramate, beta-blockers, TCAs, or Botox for chronic migraine). * **Clinical Context:** This patient has already failed two classes (topiramate and amitriptyline) and has Medication Overuse Headache (MOH) due to triptans, making her an ideal candidate for CGRP-targeted therapy. **2. Evidence for Anti-CGRP mAbs and Gepants** * **CGRP mAbs:** Large Phase 3 trials (STRIVE, LIBERTY, REGAIN) demonstrated a 50% or greater reduction in monthly migraine days (MMD) in roughly 40-50% of patients. Notably, they are effective even in patients with MOH and have a significantly better side-effect profile than traditional oral preventives. * **Gepants (Oral CGRP Antagonists):** * **Atogepant:** Approved for daily preventive use in both episodic and chronic migraine. * **Rimegepant:** Approved for every-other-day use for migraine prevention (and PRN for acute treatment). * **Role:** Often used when patients prefer oral medications or have contraindications/intolerance to mAbs. **3. Cardiovascular Considerations** CGRP is a potent vasodilator and plays a protective role during myocardial or cerebral ischemia. * **Hypertension:** Erenumab (which targets the CGRP receptor) has been associated with new-onset or worsening hypertension in some patients. Monitoring blood pressure is mandatory. * **Vasoconstriction Risk:** While CGRP pathway drugs do not cause direct vasoconstriction (unlike triptans), they should be used with caution in patients with significant active cardiovascular or cerebrovascular disease, as they might impair the body's compensatory vasodilatory response during an ischemic event. * **Raynaud’s Phenomenon:** There are emerging reports of worsening Raynaud’s or ischemic digital changes with CGRP inhibitors. **4. Management Strategy for MOH** The initiation of a CGRP mAb often leads to a spontaneous reduction in acute medication use. Guidelines increasingly favor "preventive-led" detoxification rather than abrupt triptan withdrawal alone. **References:** 1. American Headache Society. The American Headache Society Position Statement On Integrating New Migraine Treatments Into Clinical Practice. *Headache*. 2024. 2. Silberstein SD, et al. Evidence-based guideline update: Adjuvant treatment for episodic migraine in adults. *Neurology*. 2012 (updated standards). 3. Goadsby PJ, et al. A Controlled Trial of Erenumab for Episodic Migraine. *N Engl J Med*. 2017.