Sumatriptan: migraine treatment, uses and cautions

Sumatriptan treats migraine and cluster headaches once an attack has begun. The NHS says it relieves the headache and also the nausea, vomiting and sensitivity to light and sound that often accompany one. It is an acute treatment, which means it is for the attack itself and is separate from daily preventers.

The NHS does not explain the mechanism in detail. It names Imigran as the brand, and says most types need a prescription, with some tablets sold over the pharmacy counter to people who have a migraine diagnosis.

Three forms are described. Tablets are swallowed whole with water. The nasal spray goes into one nostril. The injection is self-administered into the thigh or upper arm, which suits people whose migraines come with vomiting that makes tablets unreliable.

Timing matters more than the form. The NHS says to take it as soon as possible after the migraine starts. If the first dose helps but the headache returns, a second dose can follow after at least 2 hours for tablets or spray and at least 1 hour for the injection. Your prescriber or the leaflet sets the maximum for you.

The NHS describes the medicine as working within 30 minutes to 2 hours of taking it. It aims to ease the headache and its accompanying symptoms rather than to remove every trace of the attack.

It will not stop a migraine from starting so follow the instructions from your prescriber or pharmacist on exactly when in the attack to take it.

An important warning on the NHS page is that taking sumatriptan too often can make headaches worse. This is usually called medication overuse headache. If your migraines are becoming more frequent or more intense, speak to a doctor rather than taking more.

A headache diary showing how often you treat attacks is a practical way to spot a pattern. The guides on migraine and chronic migraine on this site cover preventive approaches in general terms.

Common effects listed by the NHS are feeling flushed, tiredness and weakness, nausea, vomiting, dizziness, shortness of breath and muscle pain. If dizzy or tired, avoid driving, cycling or machinery until it passes.

Rare serious effects are anaphylaxis, and a heart attack with severe pain or tightness in the chest. The NHS says to call 999 if you suspect either. For other serious effects use NHS 111. If you think you have taken too much, call NHS 111.

Sumatriptan narrows blood vessels, so the NHS lists several conditions that make it unsuitable or call for care.

• Heart, liver or kidney conditions.

• A previous stroke or transient ischaemic attack (TIA).

• High blood pressure and peripheral vascular disease.

• A history of seizures.

• An earlier allergic reaction to sumatriptan.

The NHS names ergotamine and other triptans, SSRI and SNRI antidepressants, lithium and St John's wort as medicines or products that may interact. Say so if you use any of them. No alcohol restriction is stated on the NHS page.

For pregnancy, speak to a doctor beforehand. While breastfeeding, the NHS advises waiting at least 12 hours after a dose before feeding.

Not everyone responds to the same triptan, and other acute treatments and preventers exist. The treating clinician decides, and the migraine and headache treatment guide on this site gives context on what is available, without making a recommendation for you.