Oskela
Get started

Drug Reference

sumatriptan

Triptan· Brands: Imigran, Imitrex, Sumavel DosePro, Zembrace SymTouch, Tosymra, Onzetra XsailNASPOSC

Mechanism of action
Sumatriptan is a selective agonist at serotonin 5-HT1B and 5-HT1D receptors. Activation of 5-HT1B receptors on cranial vascular smooth muscle causes vasoconstriction of dilated cerebral and meningeal vessels. Activation of 5-HT1D receptors on trigeminal sensory nerve endings inhibits release of calcitonin gene-related peptide and other neuropeptides, reducing neurogenic inflammation and pain transmission. It is not a general analgesic and has no useful effect in tension-type headache.
Pharmacokinetics
After subcutaneous injection, peak plasma concentration occurs in about 10 to 12 minutes and bioavailability is about 96%. After oral administration, peak plasma concentration occurs at about 2 hours and bioavailability is about 14% because of presystemic metabolism and first-pass effect. Intranasal administration gives peak concentrations at about 1 to 1.5 hours with bioavailability around 16%. Protein binding is low, about 14 to 21%. Sumatriptan is metabolised mainly by monoamine oxidase A to an inactive indole acetic acid metabolite, with little involvement of cytochrome P450 enzymes. Elimination half-life is about 2 hours. Metabolites and some unchanged drug are excreted in urine. Monoamine oxidase A inhibitors markedly increase exposure and are contraindicated.
Indications & dosing

Acute migraine attack with or without aura

May repeat after at least 2 hours; maximum 300 mg in 24 hours. Review if no response after 1 to 2 doses. Not for prophylaxis.

  • adult · PO: 50–100 mg PRN, repeat once · May repeat after at least 2 hours; maximum 300 mg in 24 hours. Review if no response after 1 to 2 doses. Not for prophylaxis.

Acute migraine attack with or without aura

May repeat once after at least 1 hour; maximum 12 mg in 24 hours. Rapid onset; used when oral route unsuitable.

  • adult · SC: 6 mg PRN, repeat once · May repeat once after at least 1 hour; maximum 12 mg in 24 hours. Rapid onset; used when oral route unsuitable.

Acute migraine attack with or without aura

May repeat once after at least 2 hours; maximum 40 mg in 24 hours. Lower strengths may be available in some regions.

  • adult · INH: 20 mg PRN, repeat once · May repeat once after at least 2 hours; maximum 40 mg in 24 hours. Lower strengths may be available in some regions.

Acute cluster headache episode

Maximum 12 mg in 24 hours. Subcutaneous route preferred; may repeat once after at least 1 hour. Not for prophylactic use.

  • adult · SC: 6 mg PRN, repeat once · Maximum 12 mg in 24 hours. Subcutaneous route preferred; may repeat once after at least 1 hour. Not for prophylactic use.

Acute migraine attack with or without aura

Adolescents 12 to 17 years. UK/EU: 10 mg into one nostril, may repeat once after 2 hours, maximum 20 mg in 24 hours. Regional approval varies.

  • pediatric · INH: 10 mg PRN, repeat once · Adolescents 12 to 17 years. UK/EU: 10 mg into one nostril, may repeat once after 2 hours, maximum 20 mg in 24 hours. Regional approval varies.
Contraindications & precautions
  • Ischaemic heart disease (including history of myocardial infarction, angina, or Prinzmetal angina) · Risk of coronary vasospasm; sumatriptan can provoke ischaemia.
  • Cerebrovascular disease (stroke, transient ischaemic attack) · May increase risk of cerebrovascular events.
  • Peripheral vascular disease · Can cause vasoconstriction.
  • Uncontrolled hypertension · May exacerbate hypertension.
  • Severe hepatic impairment · Reduced clearance increases exposure.
  • Hemiplegic, basilar, or ophthalmoplegic migraine · Theoretical risk of stroke; avoid use.
  • Use within 24 hours of ergotamine, ergot derivatives, or another triptan · Additive vasoconstriction.
  • Use within 2 weeks of a monoamine oxidase inhibitor (MAOI) · Risk of hypertensive crisis and serotonin syndrome.
  • Use only for acute treatment of migraine; not for prophylaxis. Do not exceed recommended doses: oral maximum 300 mg in 24 hours, subcutaneous maximum 12 mg in 24 hours, intranasal maximum 40 mg in 24 hours. Separate doses by at least 2 hours (oral), 1 hour (subcutaneous), or 2 hours (intranasal).
  • Assess cardiovascular risk before prescribing. Do not use in patients with risk factors for coronary artery disease unless a cardiovascular evaluation has excluded coronary disease. Advise patients to report chest pain or tightness immediately.
  • Caution in hepatic impairment: reduce dose in mild to moderate; avoid in severe. Caution in renal impairment: reduce dose in severe.
  • Avoid concomitant use with ergotamine, ergot derivatives, other triptans, and MAO inhibitors. Observe washout periods: 24 hours for ergots and triptans, 2 weeks for MAOIs. Caution with SSRIs or SNRIs due to risk of serotonin syndrome.
  • Limit use to fewer than 10 days per month to prevent medication overuse headache. If attack frequency increases, review the diagnosis and consider prophylactic treatment.
  • Caution in pregnancy and breastfeeding: use only if clearly needed. Data from pregnancy registries do not show a consistent increase in major malformations, but use should be minimised.
Adverse effects
  • Paraesthesia, warmth, heaviness, pressure, or tightness in chest, throat, neck, or jaw
  • Dizziness, drowsiness, or fatigue
  • Nausea or vomiting
  • Flushing
  • Injection site pain or reaction (subcutaneous use)
  • Coronary vasospasm, myocardial infarction, or arrhythmiasserious
  • Cerebrovascular events (e.g., stroke, subarachnoid haemorrhage)serious
  • Serotonin syndrome (with concomitant serotonergic drugs)serious
  • Hypertensive crisisserious
  • Medication overuse headache
Interactions
  • fluoxetinemajorPrescribers should be cautious, especially if the patient requires both drugs. Consider alternative treatments where possible. If co-prescription is necessary, closely monitor the patient for emerging symptoms of serotonin syndrome, particularly in the first days of therapy or after dose changes. Advise the patient to seek medical attention if they experience symptoms such as confusion, sweating, tremors, or muscle twitching. Consider dose reduction of sumatriptan or fluoxetine, or using a different triptan or antiemetic.
  • sertralinemajorIf co-prescription is necessary, monitor patients closely for signs and symptoms of serotonin syndrome. Counsel the patient to seek immediate medical attention if they experience agitation, hallucinations, rapid heart rate, fever, muscle twitching, or diarrhea. Consider alternative migraine therapy with a drug lacking serotonergic activity, such as a nonsteroidal anti-inflammatory agent or an antiemetic. If serotonin syndrome is suspected, stop both drugs and initiate supportive care. Ensure the patient's history is reviewed for other serotonergic medications.
Renal & hepatic adjustment
  • eGFR 15+: No dose adjustment required. Sumatriptan is extensively metabolised in the liver, and renal impairment has minimal effect on clearance.
  • eGFR 0–14.9: Severe renal impairment (eGFR less than 15 mL/min/1.73 m2): no specific dose adjustment, but use with caution because data are limited. Monitor for adverse effects. Some local formularies advise avoiding.
  • Hepatic impairment (mild): No dose adjustment required.
  • Hepatic impairment (moderate): No dose adjustment required; use with caution and monitor for adverse effects.
  • Hepatic impairment (severe): Contraindicated. Avoid use in severe hepatic impairment due to risk of accumulation and toxicity. (avoid)
Monitoring, pregnancy & toxicity
  • Symptom relief (headache severity, nausea, photophobia, phonophobia) · 1-2 hours after dose; if no relief, do not repeat for the same attack.
  • Cardiovascular symptoms (chest pain, tightness, shortness of breath, palpitations) · During and after each dose, especially in patients with risk factors for coronary artery disease.
  • Blood pressure · Baseline and periodically if used frequently or in patients with hypertension.
  • Medication overuse headache · Review monthly; limit use to fewer than 10 days per month.
  • Serotonin syndrome signs (agitation, confusion, tremor, myoclonus, hyperreflexia, diaphoresis) · When used with SSRIs, SNRIs, MAOIs, or other serotonergic drugs.
  • Injection site reactions (pain, redness, swelling) · After subcutaneous administration.
  • Pregnancy: Sumatriptan is generally considered acceptable for acute migraine in pregnancy when simpler measures have failed. Observational data have not shown a clear increase in major congenital malformations. Use the lowest effective dose for the shortest duration. Avoid unless clearly needed. Practice varies by region; check local formulary and specialist advice.
  • Toxicity: Hypertension, tachycardia or bradycardia, and chest pain due to coronary vasospasm. · Monitor vital signs and ECG. Treat severe hypertension with standard agents. Nitrates may relieve vasospasm but can cause hypotension.
  • Toxicity: Serotonin syndrome when combined with SSRIs, SNRIs, MAOIs, or other serotonergic drugs. · Stop serotonergic drugs. Provide supportive care. Consider cyproheptadine in severe cases.
  • Toxicity: Seizures, tremor, drowsiness, dizziness, nausea and vomiting. · Supportive care. Use benzodiazepines for seizures. Activated charcoal if recent large ingestion.
  • Toxicity: No specific antidote; sumatriptan is not significantly removed by haemodialysis. · Treatment is supportive and symptomatic. Admit for monitoring if significant overdose or if symptoms are severe.
Clinical notes
Sumatriptan is for acute treatment of migraine with or without aura and for acute treatment of cluster headache by subcutaneous injection. It is not for prophylaxis and must not be used for hemiplegic, basilar or ophthalmoplegic migraine, or for headache that is not migraine. It is contraindicated in ischaemic heart disease, coronary vasospasm, previous myocardial infarction, uncontrolled hypertension, previous stroke or transient ischaemic attack, peripheral arterial disease, severe hepatic impairment, and within 24 hours of ergotamine or another triptan. Avoid with monoamine oxidase A inhibitors and for 2 weeks after stopping them. Caution is needed in people with cardiovascular risk factors; first dose may need clinical supervision in those with risk factors. Common effects include tingling, warmth, heaviness, chest or throat tightness, dizziness, drowsiness, and injection site reactions. Serotonin syndrome can occur with SSRIs, SNRIs, and other serotonergic drugs. Medication overuse headache may develop with frequent use. Teaching doses: oral 50 to 100 mg at onset, may repeat once after 2 hours, maximum 300 mg in 24 hours; subcutaneous 6 mg, may repeat once after 1 hour, maximum 12 mg in 24 hours; intranasal 10 to 20 mg, may repeat once after 2 hours, maximum 40 mg in 24 hours. If the first dose is ineffective, do not take a second dose for the same attack; reconsider the diagnosis. Practice varies by region and formulary. Sumatriptan is used in pregnancy only if the benefit outweighs the risk; breastfeeding is usually avoided for 12 hours after a dose.

Log in to read the full sumatriptan monograph

A free account unlocks the complete drug reference, the interaction checker, prescription practice and every other learning tool.

Log inCreate a free account

BNF; local formulary; current prescribing information