Sumatriptan

Mechanism of action

• Selective 5-HT1B and 5-HT1D receptor agonist (a triptan).
• It acts on cranial and meningeal blood vessels and trigeminal nerve terminals to:
  • produce cranial vasoconstriction, mainly via 5-HT1B receptors
  • inhibit trigeminal neurotransmission
  • reduce release of vasoactive neuropeptides, including CGRP, thereby decreasing neurogenic inflammation and pain signaling.
• It is used to abort an acute attack, not to prevent future migraines.
  Katzung's Basic and Clinical Pharmacology, 16th ed., p. 464.

Therapeutic uses

1. Acute migraine attack, with or without aura
2. Acute cluster headache, especially subcutaneous or intranasal forms
3. It does not treat hemiplegic or basilar migraine and is not for routine migraine prophylaxis.

Adverse effects

• Tingling or paresthesia
• Dizziness, fatigue, drowsiness
• Nausea
• Flushing or feeling warm
• Injection-site pain or reaction, with subcutaneous use
• Unpleasant/bitter taste with nasal formulations
• Sensation of heaviness, pressure, tightness, or discomfort in the chest, throat, neck, or jaw

• Coronary vasospasm, angina, myocardial ischemia, or MI
• Arrhythmias
• Increase in blood pressure, rarely hypertensive crisis
• Peripheral or gastrointestinal ischemia
• Stroke or other cerebrovascular events, rarely
• Serotonin syndrome, particularly with serotonergic drugs such as SSRIs, SNRIs, MAO inhibitors, or some TCAs
• Hypersensitivity, including angioedema or anaphylaxis
• Seizures, rarely
• Medication-overuse headache if used frequently

Key contraindications

• Ischemic heart disease, prior MI, coronary vasospasm/Prinzmetal angina
• Prior stroke or TIA
• Peripheral vascular disease or ischemic bowel disease
• Uncontrolled hypertension
• Hemiplegic or basilar migraine
• Severe hepatic impairment
• Use of an ergot drug or another triptan within 24 hours
• Current, or recent use within 2 weeks, of an MAO-A inhibitor
• Known hypersensitivity to sumatriptan