**Question:** Drugs used in prophylaxis of migraine are all except

A. Calcitonin gene-related peptide (CGRP) receptor antagonists
B. Beta-blockers
C. Calcium channel blockers
D. Antiepileptic drugs (AEDs)

**Correct Answer: B. Beta-blockers**

**Core Concept:** Prophylaxis of migraine involves medications that reduce the frequency and severity of migraine attacks. Prophylactic treatments aim to stabilize the migraine process and prevent migraines from occurring.

**Why the Correct Answer is Right:** Beta-blockers, such as propranolol and timolol, are commonly used in the management of hypertension, angina, and arrhythmias. However, they are not considered ideal for migraine prophylaxis. This is because beta-blockers primarily target the sympathetic system, which may increase the frequency and duration of migraine attacks. Additionally, beta-blockers have limited efficacy in reducing migraine frequency and severity.

**Why Each Wrong Option is Incorrect:**

**A. Calcitonin gene-related peptide (CGRP) receptor antagonists:** CGRP is a neuropeptide involved in migraine pathogenesis, and its antagonists, such as erenumab, fremanezumab, and galcanezumab, are highly effective in migraine prophylaxis. These drugs block the CGRP receptor, thereby preventing the activation of trigeminal neurons and reducing migraine attacks.

**C. Calcium channel blockers:** Calcium channel blockers, such as verapamil and nifedipine, are primarily used for treating hypertension, angina, and arrhythmias. They are not considered first-line therapy for migraine prophylaxis due to their limited efficacy and potential side effects.

**D. Antiepileptic drugs (AEDs):** AEDs, such as valproate and carbamazepine, are primarily used for treating epilepsy and other neurological disorders. They are not commonly used for migraine prophylaxis as they may have limited efficacy and unwanted side effects, such as sedation and gastrointestinal issues.

**Clinical Pearl:** The selection of migraine prophylactic medications should be tailored to the individual patient's specific migraine characteristics and comorbidities. Consulting a neurologist or headache specialist is essential for appropriate diagnosis and treatment planning.