For over two decades, triptans like sumatriptan and rizatriptan have served as the frontline abortive treatment for moderate-to-severe migraine attacks. By acting as agonists at $5\text{-HT}_{1\text{B}/1\text{D}}$ serotonin receptors, triptans constrict cranial blood vessels and inhibit pain pathways. However, this vasoconstrictive mechanism limits their use in patients with hypertension, ischemic heart disease, or stroke history, while frequently causing uncomfortable "triptan sensations" such as chest tightness, paresthesias, and flushing.
To address these limitations, researchers investigated CGRP receptor antagonists as non-vasoconstrictive alternatives. In a large-scale, long-term safety study comparing oral telcagepant (280/300 mg) to rizatriptan (10 mg) across thousands of migraine attacks over 18 months, investigators carefully documented side effect profiles and overall patient tolerability.
The comparative findings revealed a clear advantage in tolerability for the CGRP antagonist group. Patients treated with telcagepant experienced significantly fewer drug-related adverse events and triptan-specific side effects compared to those taking rizatriptan. Common symptoms such as nausea, dizziness, and dry mouth were reported at similar, low frequencies between groups, but telcagepant lacked the characteristic chest tightness and vascular side effects associated with triptan therapy.
From an acute efficacy standpoint, clinical trials evaluating CGRP antagonists demonstrated robust pain freedom and relief at two hours post-dose, alongside sustained relief up to 24 hours. This evidence confirmed that targeting neurogenic inflammation and peptide release is just as effective as direct vasoconstriction for acute abortive therapy, offering a safer alternative for patient populations requiring cardiovascular precautions.