Sumatriptan: 5-HT₁B/₁D Agonist for Acute Migraine
Sumatriptan was the first triptan approved for acute migraine treatment and remains one of the most widely used. As a selective 5-HT₁B/₁D receptor agonist, it constricts dilated cranial blood vessels and inhibits trigeminal nociceptive signal transmission.
Available as oral tablets, subcutaneous injection, and nasal spray, sumatriptan allows flexible administration based on attack severity. The subcutaneous formulation also treats acute cluster headache.
Mechanism of Action
5-HT₁B receptor activation on meningeal vessels produces vasoconstriction of dilated arteries. Simultaneously, 5-HT₁D receptor activation on trigeminal nerve endings reduces release of CGRP and substance P, interrupting the trigeminovascular pain cascade.
Indications & Use
Acute treatment of migraine with or without aura in adults. Subcutaneous sumatriptan for acute cluster headache. Not indicated for migraine prevention. Most effective when taken early in the attack.
Dosage
Oral: 50 mg at onset; may repeat after 2 hours if partial response (max 300 mg/24 h). Subcutaneous: 6 mg (may repeat after 1 hour, max 12 mg/24 h). Nasal spray: 10–20 mg per nostril. Not recommended in severe hepatic impairment.
Side Effects
Common: tingling, flushing, chest tightness/pressure sensations ('triptan sensations'), dizziness, fatigue, nausea. Serious but rare: coronary vasospasm, serotonin syndrome with serotonergic drugs, medication overuse headache with frequent use.
Drug Interactions
MAO-A inhibitors (moclobemide): significantly increase sumatriptan levels — contraindicated. Ergotamine: vasoconstriction risk — separate by ≥6 hours. SSRIs/SNRIs: serotonin syndrome risk. Other triptans: do not combine within 24 hours.
Contraindications
Ischaemic heart disease, coronary vasospasm (Prinzmetal's angina), stroke/TIA, peripheral vascular disease, uncontrolled hypertension, severe hepatic impairment, hemiplegic/basilar migraine, hypersensitivity.
Frequently Asked Questions
When should I take sumatriptan?
At the onset of migraine headache — not during the aura phase. Taking it too early (during aura) or too late reduces efficacy.
Why is sumatriptan limited to two doses per day?
To limit cardiovascular risk from repeated vasoconstriction and prevent medication overuse headache (MOH). Using triptans >10 days/month can cause rebound headache.
Can I take sumatriptan during pregnancy?
Evidence is limited. Most guidelines consider it acceptable for severe attacks when benefits outweigh risks. Paracetamol is preferred first-line. Always consult your doctor.
References
- EMA prescribing information for sumatriptan
- European Headache Federation Guidelines 2021
- DMKG Leitlinien Migräne
Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice.