Pharmacology · Cardiovascular

CGRP Pharmacology and Migraine Therapeutics

Migraine mechanism, gepant and antibody drug classes, and cardiovascular safety

Calcitonin gene-related peptide is the dominant neuropeptide mediating migraine pain — released from trigeminal sensory fibers innervating meningeal blood vessels, it produces vasodilation, neurogenic inflammation, and mast cell activation; CGRP levels are elevated in jugular venous blood during attacks and normalize with effective treatment, establishing it as a causal mediator rather than a bystander.
Gepants are small-molecule CGRP receptor antagonists that block the receptor without vasoconstriction — the fundamental pharmacological advantage over triptans that makes them safe in patients with cardiovascular disease, stroke, or uncontrolled hypertension where triptans are contraindicated; ubrogepant and rimegepant are approved for acute treatment, while rimegepant (dual-use) and atogepant are approved for prevention.
The monoclonal antibodies against CGRP target either the receptor itself (erenumab, which blocks the RAMP1 component of the CGRP receptor) or the CGRP peptide (fremanezumab, galcanezumab, eptinezumab); all are prevention-only agents given subcutaneously monthly or quarterly, with eptinezumab administered intravenously quarterly — their long half-lives make them uniquely suited to prevention rather than acute rescue.
Rimegepant is the only CGRP-targeting agent with dual approval — acute treatment of individual attacks and prevention when taken every other day; this flexibility makes it clinically useful for patients who need both functions without adding a separate preventive injection, though it is more expensive than oral small-molecule preventives for patients using it only for prevention.
A caution applies to monoclonal antibodies in patients with established cardiovascular disease: CGRP is a vasodilator with a role in coronary and cerebrovascular autoregulation, and patients with recent MI or stroke were excluded from pivotal trials — the long-term cardiovascular safety of sustained CGRP pathway blockade is not fully characterized, whereas gepants, with their shorter duration of action, do not share this theoretical concern.

Feature	Ubrogepant	Rimegepant	Atogepant	Erenumab	Fremanezumab / Galcanezumab / Eptinezumab
Class	Gepant	Gepant	Gepant	Monoclonal antibody	Monoclonal antibody
Target	CGRP receptor	CGRP receptor (RAMP1)	CGRP peptide
Acute use	Yes	Yes	No	No	No
Preventive use	No	Yes	Yes	Yes	Yes
Route	Oral	Oral (ODT)	Oral	SC monthly	SC monthly/quarterly; IV quarterly (eptinezumab)
Vasoconstriction	No	No	No	No	No
Safe in CV disease	Yes	Yes	Yes	Caution*	Caution*
Key adverse effect	Nausea	Nausea	Constipation, nausea	Constipation, injection site reaction	Injection site reaction

Suggested References

Author / Organization	Title	Source
Katzung BG, ed.	Basic and Clinical Pharmacology. 15th ed.	McGraw-Hill; 2021
Brunton LL, Knollmann BC, eds.	Goodman & Gilman's The Pharmacological Basis of Therapeutics. 14th ed.	McGraw-Hill; 2023
Edvinsson L, Haanes KA, Warfvinge K, Krause DN.	CGRP as the target of new migraine therapies — successful translation from bench to clinic.	Nat Rev Neurol. 2018;14(6):338–350
Goadsby PJ, Edvinsson L, Ekman R.	Vasoactive peptide release in the extracerebral circulation of humans during migraine headache.	Ann Neurol. 1990;28(2):183–187
Goadsby PJ, Holland PR, Martins-Oliveira M, Hoffmann J, Schankin C, Akerman S.	Pathophysiology of migraine: a disorder of sensory processing.	Physiol Rev. 2017;97(2):553–622
Lipton RB, Dodick DW, Ailani J, et al.	Effect of ubrogepant vs placebo on pain and the most bothersome associated symptom in the acute treatment of migraine: the ACHIEVE II randomized clinical trial.	JAMA. 2019;322(19):1887–1898
Croop R, Lipton RB, Kudrow D, et al.	Oral rimegepant for preventive treatment of migraine: a phase 2/3, randomised, double-blind, placebo-controlled trial.	Lancet. 2021;397(10268):51–60
Ailani J, Lipton RB, Goadsby PJ, et al.	Atogepant for the preventive treatment of migraine.	N Engl J Med. 2021;385(8):695–706
Ashina M, Goadsby PJ, Reuter U, et al.	Long-term efficacy and safety of erenumab in migraine prevention: results from a 5-year, open-label treatment phase.	Eur J Neurol. 2021;28(5):1716–1725
Ailani J, Burch RC, Robbins MS; Board of Directors of the American Headache Society.	The American Headache Society Consensus Statement: update on integrating new migraine treatments into clinical practice.	Headache. 2021;61(7):1021–1039