Mechanism of action
Sumatriptan selectively binds to and activates serotonin 5-HT1B and 5-HT1D receptors located on cranial blood vessels and sensory nerves of the trigeminal system.
5-HT1B receptor activation causes vasoconstriction of dilated intracranial extracerebral blood vessels, particularly in the meningeal and cerebral vasculature. This reverses the vasodilation that contributes to migraine pain.
5-HT1D receptor activation occurs on trigeminal nerve terminals and inhibits the release of pro-inflammatory neuropeptides including calcitonin gene-related peptide (CGRP), substance P, and neurokinin A. This prevents neurogenic inflammation in the meninges and blocks transmission of pain signals through the trigeminal pathway to central pain centers.
The combination of cranial vasoconstriction and inhibition of trigeminovascular system activation provides effective relief of migraine headache and associated symptoms. Sumatriptan does not prevent migraines and has no effect on migraine frequency; it is purely an abortive agent.
- Sumatriptan is a selective 5-HT1B/1D agonist that causes cranial vasoconstriction and inhibits trigeminal neuropeptide release
- Contraindicated in ischemic heart disease, uncontrolled hypertension, and within 24 hours of ergot derivatives or other triptans
- Chest tightness occurs in 3-5% of patients; usually non-cardiac but requires evaluation if severe or new
- Metabolized by MAO-A; contraindicated with MAOIs due to risk of hypertensive crisis
- Risk of serotonin syndrome when combined with SSRIs, SNRIs, or other serotonergic agents
- Use on more than 10 days per month can cause medication overuse headache
- Subcutaneous formulation is first-line for acute cluster headache due to rapid onset
- Most effective when taken early during mild pain phase before progression to severe migraine
Indications
Sumatriptan is FDA-approved for:
- Acute migraine treatment with or without aura in adults and adolescents (intranasal spray approved for ages 12 and older; oral, subcutaneous, and transdermal for ages 18 and older)
- Acute cluster headache treatment (subcutaneous formulation only)
Sumatriptan is most effective when taken early in the migraine attack, ideally during mild pain before progression to moderate or severe intensity. It is not indicated for migraine prophylaxis, hemiplegic migraine, basilar migraine, or management of chronic daily headache.
Available formulations include oral tablets, subcutaneous injection, intranasal spray, and transdermal patch. Subcutaneous administration provides the fastest onset and highest efficacy but also the highest rate of adverse effects.
Pharmacokinetics
Absorption: Bioavailability varies by route. Oral bioavailability is approximately 15% due to extensive first-pass metabolism and incomplete absorption. Subcutaneous bioavailability is 97%, and intranasal is approximately 17%.
Distribution: Protein binding is low (14-21%). Volume of distribution is approximately 2.4 L/kg. Sumatriptan crosses the blood-brain barrier minimally.
Metabolism: Primarily hepatic via monoamine oxidase A (MAO-A) to an inactive indole acetic acid metabolite. The drug undergoes extensive first-pass metabolism when given orally.
Elimination: The elimination half-life is approximately 2-2.5 hours across all formulations. Approximately 60% is excreted in urine (mostly as metabolites), and 40% in feces. Renal clearance accounts for about 20% of total clearance.
Onset and duration: Subcutaneous injection provides onset within 10-15 minutes with peak effect at 1 hour. Oral tablets have onset at 30 minutes to 1 hour. Intranasal spray has intermediate kinetics. Duration of action is 4-6 hours, though headache recurrence within 24 hours occurs in 30-40% of responders.
Adverse effects
Common adverse effects
- Paresthesias and sensory symptoms: Tingling, numbness, warm or cold sensations (reported in up to 40% with subcutaneous administration)
- Chest symptoms: Chest pressure, tightness, or heaviness (occurs in 3-5% and is usually non-cardiac in origin but requires evaluation)
- Injection site reactions: Pain, redness, bruising (with subcutaneous formulation)
- Dizziness and drowsiness: Affects approximately 10-15% of patients
- Flushing and feeling of warmth
- Neck pain or stiffness
- Nausea (can be difficult to distinguish from migraine-associated nausea)
Serious adverse effects
- Coronary vasospasm and myocardial ischemia: Can precipitate angina or myocardial infarction in patients with coronary artery disease. Chest symptoms require cardiac evaluation before re-dosing.
- Cerebrovascular events: Stroke and transient ischemic attacks have been reported, particularly in patients with vascular risk factors
- Peripheral vascular ischemia: Rare cases of bowel or limb ischemia
- Hypertensive crisis: Can cause significant blood pressure elevation, especially in patients with uncontrolled hypertension
- Serotonin syndrome: Risk increases when combined with SSRIs, SNRIs, MAOIs, or other serotonergic agents
- Medication overuse headache: Develops with frequent use (>10 days per month)
- Seizures: Reported rarely in patients with and without seizure history
Formulation-specific effects
Subcutaneous injection has the highest rate of adverse effects but fastest efficacy. Nasal spray can cause nasal discomfort and taste disturbances.
Contraindications and warnings
Absolute contraindications
- Ischemic heart disease (angina, history of myocardial infarction, documented silent ischemia)
- Coronary artery vasospasm including Prinzmetal angina
- Wolff-Parkinson-White syndrome or other cardiac arrhythmias associated with accessory cardiac conduction pathways
- History of stroke, transient ischemic attack, or hemiplegic or basilar migraine
- Peripheral vascular disease including ischemic bowel disease
- Uncontrolled hypertension
- Recent use (within 24 hours) of another triptan or ergot-type medication
- Use within 2 weeks of MAO-A inhibitor discontinuation
- Hypersensitivity to sumatriptan
Warnings and precautions
Cardiovascular evaluation: Consider cardiovascular assessment before prescribing in patients with multiple cardiovascular risk factors (hypertension, hypercholesterolemia, smoking, obesity, diabetes, family history, postmenopausal women, men over 40).
Serotonin syndrome: Use caution when co-administering with SSRIs, SNRIs, TCAs, MAOIs, or other serotonergic drugs. Monitor for agitation, hallucinations, tachycardia, hyperthermia, hyperreflexia, and incoordination.
Medication overuse headache: Warn patients that use on more than 10 days per month may lead to exacerbation of headache frequency and severity.
Pregnancy: Category C. Use only if benefit justifies potential risk. Data in pregnancy are limited.
Hepatic impairment: Use with caution; consider lower doses as metabolism is reduced. Maximum single oral dose should not exceed 50 mg.
Phenylketonuria: Oral disintegrating tablets contain phenylalanine.
Drug interactions
Major interactions
Ergot-containing medications (ergotamine, dihydroergotamine, methysergide): Additive vasospastic effects. Do not use within 24 hours of each other.
Other triptans: Additive serotonergic and vasoconstrictive effects. Do not use within 24 hours of another triptan.
MAO-A inhibitors: MAO-A metabolizes sumatriptan; inhibitors significantly increase sumatriptan levels and risk of hypertensive crisis. Contraindicated within 2 weeks of MAOI use.
SSRIs and SNRIs (fluoxetine, paroxetine, sertraline, venlafaxine, duloxetine): Increased risk of serotonin syndrome. Monitor closely for symptoms including mental status changes, autonomic instability, and neuromuscular abnormalities. The interaction is possible but uncommon; many patients safely use both drug classes.
TCAs (amitriptyline, nortriptyline): May increase risk of serotonin syndrome, though less than with SSRIs/SNRIs.
Moderate interactions
St. John's wort: May increase serotonergic effects and risk of serotonin syndrome.
Propranolol and other beta-blockers: Theoretical concern for unopposed alpha-adrenergic vasoconstriction, though clinical significance is unclear.
| Interacting Drug | Mechanism | Management |
|---|---|---|
| Ergotamines | Additive vasospasm | Separate by 24 hours |
| MAOIs | Reduced metabolism | Contraindicated |
| SSRIs/SNRIs | Serotonin syndrome | Monitor closely |
| Other triptans | Additive effects | Separate by 24 hours |
Clinical pearls
Early administration is key: Sumatriptan works best when taken during mild pain phase. Efficacy decreases significantly if delayed until severe pain or after development of cutaneous allodynia.
Headache recurrence: Approximately 30-40% of initial responders experience headache recurrence within 24 hours. This reflects the drug's short half-life relative to migraine pathophysiology duration. A second dose may be taken (minimum 1-2 hours after first dose depending on formulation).
Chest symptoms evaluation: Chest pressure or tightness is common (3-5%) and usually non-cardiac, likely related to esophageal spasm or chest wall muscle tension. However, true cardiac ischemia can occur. Any new or severe chest symptoms require ECG and cardiac evaluation before re-exposure.
Subcutaneous route for cluster headache: The subcutaneous formulation is the only FDA-approved triptan for acute cluster headache and is considered first-line due to rapid onset. Oxygen therapy remains the other first-line acute treatment.
Medication overuse headache prevention: Counsel patients to limit triptan use to fewer than 10 days per month. Frequent use leads to transformation to chronic daily headache that resolves only with drug withdrawal.
Triptan non-response: Approximately 30-40% of patients do not respond to a given triptan. Non-response to one triptan does not predict non-response to others; trial of 2-3 different triptans at adequate doses may be warranted.
Combination with NSAIDs: Combining a triptan with an NSAID (such as naproxen) improves efficacy and reduces headache recurrence compared to triptan alone. This is a common and effective strategy.
Formulation selection: Choose based on patient needs. Subcutaneous provides fastest relief for severe attacks or when nausea/vomiting limits oral absorption. Nasal spray offers intermediate speed. Oral is convenient for moderate attacks without significant nausea.
Cardiovascular screening: While formal stress testing is not routinely required, consider it in patients with multiple cardiac risk factors before prescribing. First dose may be administered in a supervised medical setting in high-risk patients.
Practice questions
1. A 35-year-old woman with a history of migraine headaches presents to the emergency department with severe throbbing left-sided headache, nausea, and photophobia that began 4 hours ago. She has a history of coronary artery disease and had a myocardial infarction 6 months ago. Her current medications include aspirin, metoprolol, and atorvastatin. Blood pressure is 145/90 mmHg. Which of the following is the most appropriate acute treatment for her headache?
2. A 28-year-old man takes sumatriptan for migraine headaches approximately 4 times per month. He also takes sertraline 100 mg daily for depression. Two hours after taking sumatriptan for an acute migraine, he develops agitation, confusion, diaphoresis, tremor, and hyperreflexia. His temperature is 38.5°C (101.3°F), blood pressure is 160/95 mmHg, and heart rate is 115/min. Which of the following best explains his current presentation?
3. A 42-year-old woman has been using sumatriptan for migraine headaches with good initial relief. However, over the past 3 months, she has noticed that her headaches have become more frequent, now occurring 15-20 days per month instead of her previous 4-6 days per month. She reports taking sumatriptan on most days when headaches occur. Physical examination is unremarkable. Which of the following is the most likely cause of her increased headache frequency?
Frequently asked questions
How does sumatriptan work?
Sumatriptan works by activating 5-HT1B receptors on cranial blood vessels to cause vasoconstriction and 5-HT1D receptors on trigeminal nerve terminals to inhibit release of inflammatory neuropeptides. This dual action reverses the vasodilation and neurogenic inflammation that contribute to migraine pain. It does not prevent migraines; it only treats acute attacks by targeting the underlying pathophysiology of active migraine.
What are the side effects of sumatriptan?
Common side effects include tingling or numbness, chest pressure or tightness, dizziness, drowsiness, flushing, and injection site reactions with subcutaneous use. Serious but rare adverse effects include coronary vasospasm, myocardial infarction, stroke, hypertensive crisis, and serotonin syndrome when combined with other serotonergic drugs. Chest symptoms require cardiac evaluation before re-dosing to rule out true ischemia.
Is sumatriptan a controlled substance?
No, sumatriptan is not a controlled substance. It has no abuse potential and does not cause physical dependence. However, it can cause medication overuse headache when used on more than 10 days per month, leading to increased headache frequency. This is a pharmacological effect of frequent triptan use, not a dependence syndrome. Patients should be counseled on appropriate frequency of use.
Can I take sumatriptan with antidepressants?
Sumatriptan can be taken with SSRIs and SNRIs but carries a risk of serotonin syndrome, though this is uncommon in clinical practice. Many patients safely use both drug classes together. Monitor for symptoms including agitation, confusion, rapid heart rate, high blood pressure, dilated pupils, muscle rigidity, and hyperthermia. Sumatriptan is contraindicated with MAO inhibitors due to risk of hypertensive crisis, and must not be used within 2 weeks of stopping an MAOI.
Sumatriptan vs eletriptan — what is the difference?
Both are triptans with similar mechanisms, but eletriptan has higher oral bioavailability (50% vs 15%) and longer half-life (4 hours vs 2.5 hours), potentially providing longer duration of action and lower headache recurrence rates. Eletriptan may be more effective in some patients who do not respond to sumatriptan. However, sumatriptan is available in more formulations including subcutaneous and nasal, and has been studied more extensively. Both share similar contraindications and adverse effect profiles.
Conditions it is used for
Related drugs
Sources and further reading
DailyMed (FDA labels)StatPearls (NCBI Bookshelf)MedlinePlusWHO ATC/DDD index: N02CC01
Educational content for medical students, prepared by the WhiteCoat Pro editorial team with AI assistance; every page is reviewed by a second AI model for factual errors. It is not medical advice and does not replace the product label, local guidelines or a clinician.