What we know about CGRP in headache

Calcitonin gene related peptide (CGRP) is an ubiquitous neuropeptide found both centrally and peripherally in human nervous system. CGRP has been shown to be relevant to headache pathophysiology. It can be released during acute migraine attacks with subsequent elevations of CGRP levels in blood. The blood levels of this neuropeptide can be normalized with successful sumatriptan treatment. These findings have led to development of CGRP targeted treatments for migraine. CGRP receptor antagonists have demonstrated proof of efficacy for acute treatment of migraine CGRP monoclonal antibodies demonstrated efficacy and tolerability across both episodic and chronic migraine. CGRP monoclonal antibodies reduced the acute headache medication use days. CGRP monoclonal antibodies have demonstrated improvement in Patient-Reported Outcomes including migraine-related disability, quality of life and impact of headache on everyday life versus placebo. Role of CGRP in in the pathophysiology of chronic tension type headache has also been suggested. Human experimental studies have demonstrated elevated plasma CGRP levels during both spontaneous and glyceryl trinitrate-induced cluster headache attacks. Subsequently, the results from randomized controlled trials have reported that CGRP monoclonal antibodies are effective in reducing the number of cluster headache attacks.