Chapter 29: Drugs for Headache Disorders

The sources emphasize that migraines are the most prevalent serious headache disorder, thought to arise from neurovascular dysfunction and an imbalance between excitatory and inhibitory neuronal activity. This pathophysiology involves a two-phase process: an initial vasoconstrictive phase often associated with a visual or sensory aura, followed by a longer phase of vasodilation and intense pain driven by the trigeminal neurovascular system and the release of peptides like calcitonin gene-related peptide (CGRP). Treatment strategies are bifurcated into prophylactic measures to reduce the frequency of attacks and abortive therapies to stop them once they begin. Prevention involves a wide array of drug classes, including antiepileptics such as valproate, antidepressants like amitriptyline, beta-adrenoceptor antagonists such as propranolol, and modern CGRP-targeted monoclonal antibodies like erenumab. For acute termination, the triptan class and ergot alkaloids serve as essential serotonin receptor agonists that promote vasoconstriction and block the release of inflammatory peptides. The chapter also introduces newer options like lasmiditan, a selective 5-HT 1F agonist that avoids cardiovascular risks, and small-molecule CGRP antagonists known as gepants. Beyond migraines, the text outlines specific protocols for cluster headaches, which may involve lithium for prevention and high-flow oxygen for termination, as well as tension headaches, which are typically managed with analgesics and muscle relaxants.