Drug Therapy of Migraine (KSIU International University Lecture) PDF

Field of Medicine Medicine And Surgery Program Lecture : (Drug therapy of migraine) Dr : ( M. Habib) Date : 10 / 11 /2024 1. Design a pharmacological approach for management of acute migraine attacks. 2. List the drugs used for migraine prophylaxis. 3. Recognize the mechanism of...

Field of Medicine Medicine And Surgery Program Lecture : (Drug therapy of migraine) Dr : ( M. Habib) Date : 10 / 11 /2024 1. Design a pharmacological approach for management of acute migraine attacks. 2. List the drugs used for migraine prophylaxis. 3. Recognize the mechanism of action, uses, and adverse effects of different anti-migraine drugs.  What is Migraine? Recurrent, episodic headache, typically unilateral, associated with vomiting and visual disturbance. Four phases American Migraine Foundation, 2018 Acute Migraine Attack (Classic migraine) American Migraine Foundation, 2018 American Migraine Foundation, 2018  Two main types of migraine Migraine with aura Migraine without aura (Classic migraine) (Common migraine) American Migraine Foundation, 2018 Classification of Migraine according to severity Pathophysiology of Migraine (Not fully understood) 5-HT1F  Drugs Therapy of acute migraine attack (abortive therapy) I. Mild to moderate attacks: Over-the-counter analgesics are first line therapy for mild to moderate acute migraine NSAIDs Acetaminophen-aspirin-caffeine combination II. Moderate to severe attacks: Triptans: [1st line antimigraine therapy: for outpatients (moderate - severe)] Ergots: similar to triptans (NOT 1st line) Lasmiditan: 5-HT1F receptor agonist Rimegepant: CGRP receptor antagonists III. Antiemetics: Metoclopramide (3 advantages) IV. Remote electrical neuromodulation Mechanism of action of antimigraine drugs 5-HT1F  Triptans: Sumatriptan (prototype) Mechanism of action (selective 5-HT1B/1D agonists) 1. Activate 5HT1B/1D receptors on presynaptic trigeminal nerve →↓ release of VD neuropeptides 2. VC of dural vessels → prevent stretching of pain nerve endings Triptans are more effective in early migraine attack or when the headache is still mild  Triptans Adverse effects 1. Injection site reaction (with SC) 2. Unpleasant taste (with intranasal) 3. Chest pressure (resolves spontaneously in 30 minutes) 4. Paresthesia, drowsiness, weakness, malaise  Triptans Contraindications & Precautions: 1.Uncontrolled hypertension, ischemic stroke & IHD → 1st dose given cautiously in diabetics, hypertensives, men > 40 & in postmenopausals 2.Pregnancy 3.Drug interaction: with 5-HT drugs: SSRIs, MAOI or within 24 hrs of ergots (→ 5HT syndrome)  Ergots (Ergotamine – Dihydroergotamine) Mechanism of action: 5-HT1B/1D agonists similar to triptans Adverse effects & contraindications : 1. GIT: Nausea, vomiting, diarrhea 2. Chest pressure 3. CI. In Pregnancy 4. Prolonged Vasospasm→ gangrene (CI peripheral vascular disease), Angina 5. Long term use (Fibrosis→ valvular heart disease, Pulm.). Anti-migraine therapy should NOT exceed 10 -15 days / month to avoid Medication Overuse Headache “MOH” Ergotamines have more side effects than triptans and analgesics →They should therefore NO longer be used as the therapy of first choice  Drugs for migraine prophylaxis (Preventive Therapy) (> 2 attacks/Month) 1. Beta blockers: Propranolol, Metoprolol and Timolol (Of choice) 2. Anticonvulsants: Valproate & Topiramate (↓ Excess firing of CR V) 3. Antidepressants: Amitriptyline (TCA) 4. Angiotensin receptor blockers: Candesartan 5. Rimegepant Life-style modification stress management - rest - exercise - behavioral therapy