How sumatriptan works
Triptans such as sumatriptan enter the brain via the blood and activate certain docking sites (receptors) for the nerve messenger serotonin (5-HT1 receptor) on the surface of nerve cells and blood vessels in the brain. This causes the blood vessels, which are dilated during an attack, to constrict and also results in fewer inflammatory messenger substances being released by nerve cells.
Sumatriptan therefore has vasoconstrictor, anti-inflammatory and analgesic properties. The effect is stronger the earlier sumatriptan is administered.
Migraines are distinguished from normal headaches by a pain that is usually unilateral, severe, and pulsating to throbbing. The causes of migraine are not fully understood. Currently, experts assume several complementary factors in the development of migraine:
- During an acute migraine attack, blood vessels in the brain are demonstrably dilated, which increases the blood supply to the affected parts of the brain. There are receptors in the vessel wall that transmit pain and the dilatation of the vessels to the brain.
- Experts suspect that migraine patients suffer from hyperexcitability of certain parts of the brain. The same is the case with epileptic seizures, to which migraine has some parallels.
Absorption, degradation and excretion
After ingestion by mouth, sumatriptan is rapidly absorbed into the blood, but only in small amounts (about ten to twenty percent) across the intestinal wall. It reaches its site of action via the blood-brain barrier.
The absorption rate is higher when administered as a nasal spray or under the skin (subcutaneously) using an autoinjector, as the active substance bypasses the gastrointestinal tract here and enters the blood directly.
Sumatriptan is then largely converted in the liver to degradation products that are no longer effective and excreted via the kidneys. About two hours after ingestion, half of the original amount of active substance has already left the body.
When is sumatriptan used?
Sumatriptan is approved for the treatment of acute migraine attacks with and without aura (tablets, nasal spray, and auto-injector) and cluster headaches (auto-injector only).
How sumatriptan is used
The migraine medicine sumatriptan is usually taken as a tablet at the onset of or during an acute migraine attack. The usual dosage is 50 to 100 milligrams of sumatriptan; higher dosages show no increased effect.
If, after the first tablet has taken effect, the pain recurs after a few hours, a second tablet can be taken within a day (but no earlier than two hours after the first).
Because sumatriptan is poorly absorbed in the intestine, there are several other dosage forms on the market that provide a faster onset of action:
- Sumatriptan nasal spray is sprayed once into one nostril. If the pain recurs after a few hours, a second spray can be administered within a day. A low-dose nasal spray is available for children twelve to 17 years of age.
- Sumatriptan Injection Solution is injected into the subcutaneous fat tissue. If the pain recurs after a few hours, a second injection may be given within a day.
Sumatriptan must not be used again until at least two hours after the first dose (tablet), the first spray (nasal spray) or the first injection (autoinjector).
Nasal spray and auto-injector are particularly suitable for patients who suffer from nausea and vomiting during migraine attacks and therefore have difficulty taking tablets.
What are the side effects of sumatriptan?
Sumatriptan causes side effects such as dizziness, drowsiness, weakness, heaviness, sensory disturbances, increase in blood pressure, flushing, shortness of breath, nausea, vomiting and muscle pain in one in ten to one hundred people treated.
What should I be aware of when taking sumatriptan?
Contraindications
Sumatriptan must not be used in:
- previous heart attack or stroke
- coronary artery disease or peripheral arterial disease (CAD)
- Raynaud’s disease (paling of fingers and/or toes due to spasmodic blood vessel constriction)
- uncontrolled high blood pressure
- severe liver or kidney dysfunction
- concomitant use of ergotamines, selective serotonin reuptake inhibitors (SSRIs) or monoamine oxidase inhibitors (MAO inhibitors)
Drug Interactions
If sumatriptan is combined with other medicines for the treatment of migraine, increased undesirable effects such as cramping of the coronary arteries may occur. Such drug combinations must therefore be avoided.
Drugs that affect serotonin concentrations (e.g., various antidepressants, 5-hydroxytryptophan, tramadol, fentanyl) should not be combined with the migraine drug sumatriptan.
Age Limitation
Use in children and adolescents depends on the particular dosage form. Sumatriptan tablets may be used from the age of ten years, sumatriptan nasal spray from twelve years and sumatriptan auto-injector from 18 years.
Pregnancy and lactation
Sumatriptan passes into breast milk. A breastfeeding break of at least twelve hours is recommended after intake. Due to the irregular use, a risk to the child is not likely.
Of all the triptans, sumatriptan is the drug of choice during pregnancy and breastfeeding when the better-studied pain relievers acetaminophen and ibuprofen are not sufficiently effective.
How to obtain medicines containing sumatriptan
Preparations containing the active ingredient sumatriptan are currently still available on prescription in Germany, Austria, and Switzerland in every dosage and package size, but there are discussions about a release from prescription requirements (for low dosages and small package sizes).
Sumatriptan-containing nasal sprays are currently only available in Germany and Switzerland, but not in Austria.
Newer triptans such as naratriptan and almotriptan are already available in Germany in small packs only on a pharmacy-only basis. In Austria, zolmitriptan, the first triptan, has been available over-the-counter in pharmacies since 2021.
Since when has sumatriptan been known?
After scientific studies in the 1960s showed that vasoconstriction in the brain by various serotonin derivatives and analogues led to an improvement in migraine attacks, a targeted search for new active ingredients for this purpose began in 1972.
