The New Frontier in Migraine Treatment – CGRP Inhibitors and What You Need to Know

 Migraine: A Brief History Migraines have been described in medical literature for centuries. Historically misunderstood, migraines were often dismissed as mere headaches. Traditional treatments relied on painkillers, triptans, and lifestyle modifications, offering limited effectiveness for chronic sufferers. The discovery of calcitonin gene-related peptide (CGRP) and its role in migraine pathology revolutionised migraine treatment and understanding.

Understanding Migraines: Causes and Demographics Migraines are complex neurological conditions characterised by intense, debilitating headaches often accompanied by nausea, vomiting, sensitivity to light and sound, and visual disturbances (auras). Although the exact cause remains unclear, genetics and environmental factors play significant roles. Migraines typically affect individuals aged between 18-55, disproportionately impacting women (three times more common than in men). Hormonal changes, stress, diet, and environmental triggers are common contributors.

Diagnosis of Migraine Migraine diagnosis primarily relies on clinical history and symptom presentation. Clinicians assess headache patterns, frequency, duration, associated symptoms, and triggers. Diagnostic criteria set by the International Headache Society aid healthcare professionals in accurately diagnosing migraines. Occasionally, neuroimaging (MRI or CT scans) may rule out other neurological conditions but are not routinely necessary.

CGRP and the Science Behind Migraine Symptoms CGRP is a neuropeptide widely distributed in the central and peripheral nervous systems, particularly within the trigeminal nerve, responsible for facial and cranial sensation. During migraine episodes, elevated CGRP levels induce inflammation and dilation of cerebral blood vessels, causing pain, nausea, and other migraine symptoms.

The CGRP Drugs Changing the Migraine Treatment Landscape Since 2018, revolutionary drugs targeting CGRP pathways have transformed migraine management. These medications, including monoclonal antibodies (mAbs) and small-molecule antagonists (gepants), specifically target CGRP or its receptor, preventing or reducing migraine frequency and intensity.

Detailed Overview of CGRP Drugs

• Erenumab (Aimovig): A monoclonal antibody administered monthly via injection, directly blocking the CGRP receptor to prevent migraines.
• Fremanezumab (Ajovy) and Galcanezumab (Emgality): Monoclonal antibodies targeting the CGRP ligand itself, delivered via monthly or quarterly injections, significantly reducing migraine occurrence.
• Eptinezumab (Vyepti): Administered as an intravenous infusion every three months, this monoclonal antibody rapidly and effectively prevents migraine episodes by targeting CGRP directly.
• Rimegepant & Ubrogepant: Oral gepants used to acutely treat migraine episodes, these small-molecule CGRP receptor antagonists block CGRP activity swiftly, providing immediate relief during migraine attacks. Rimegepant additionally offers preventative benefits when taken regularly.
• Atogepant: An oral preventative gepant that significantly reduces migraine frequency through regular, daily administration by blocking CGRP receptors.

Risks & Side Effects

• Common: Injection site reactions, constipation, fatigue, and minor nausea.
• Rare: Hypersensitivity or allergic reactions, exacerbation of hypertension (particularly with erenumab).
• These medications generally exhibit a significantly more favourable side effect profile compared to traditional migraine therapies.

Benefits of CGRP Inhibitors

• Directly target migraine pathology for more precise relief.
• Long-acting efficacy through monthly, quarterly, or regular oral administration.
• Reduced reliance on traditional painkillers and triptans, reducing associated side effects and risks of medication-overuse headaches.

NICE Guidelines (UK) According to the National Institute for Health and Care Excellence (NICE), CGRP inhibitors are recommended for patients experiencing chronic migraine, defined as 15 or more headache days per month, who have failed to respond adequately to at least three previous preventative treatments. NICE recommends erenumab, fremanezumab, and galcanezumab specifically, with initial treatment effectiveness evaluated after 12 weeks. Treatment continuation requires evidence of a 30-50% reduction in migraine frequency.

Final Thoughts Migraine treatment is evolving rapidly. CGRP inhibitors offer substantial promise and hope for chronic migraine sufferers, providing targeted relief with fewer side effects. For healthcare professionals, especially those specialising in orofacial pain, dentistry, or neurology, understanding migraine’s complexity and available treatments is crucial for providing comprehensive, multidisciplinary care.

At Tracey Bell Clinic, we remain dedicated to advancing care by embracing innovative, evidence-based solutions to significantly enhance patient well-being and quality of life.