Sumatriptan (injection)

Sumatriptan is used to ease the symptoms of migraine or cluster headaches. Find out how to use it safely and possible side effects. Sumatriptan injection is also called Imigran.

Type of medicine	Also called
Migraine treatment Belongs to a group of medicines known as triptans	Imigran® Clustran®

What is sumatriptan?

Sumatriptan is used to ease the symptoms of migraine or cluster headaches. It works by releasing a natural chemical called serotonin, which causes the blood vessels around your brain to contract (narrow). This reverses the dilating (widening) of blood vessels that's believed to be part of the headache process.

Sumatriptan only works when a migraine attack has already begun. It will not prevent a migraine. Do not take it before your headache begins, or during the aura phase, as it may be less effective. Read more about migraine headaches.

Sumatriptan belongs to a group of medicines called triptans. In New Zealand, sumatriptan is available as tablets (50 mg and 100 mg) and an injection. The information on this page is about sumatriptan injection. Read more about sumatriptan tablets.

Dose

Using the autoinjector device, inject a single injection (6 mg) at the start of the migraine attack. It should work within 10–15 minutes.
If your migraine improves at first but comes back, wait at least 1 hour before giving yourself another injection (6 mg).
Do not use more than 2 injections (12 mg) in 24 hours.
If the first sumatriptan dose does not relieve or help your migraine, don't take another sumatriptan dose for this same attack. It is unlikely to work.

Monthly limit

Using sumatriptan too frequently can cause medication overuse headache or rebound headache. This headache is caused by overuse of painkillers to treat headache, including the use of triptans for migraine.

The symptoms include a tension-type headache or migraine-like attack. Headaches often improve within 7–10 days after sumatriptan has been stopped. Symptoms may be worse before an improvement is seen. To avoid this, don't use sumatriptan for more than 10 days per month.

How to use sumatriptan

Note: The funded brand of sumatriptan injection has changed from Sun-Pharma or Clustran prefilled pens to Imigran prefilled pens (September 2020).

Timing: It is best to use sumatriptan injection as soon as you notice headache symptoms, but you can also use it after a migraine has already begun. Sumatriptan injection usually starts to work within 10–15 minutes after the injection is given.
Ask your doctor, nurse or pharmacist to show you how to use the sumatriptan autoinjector device. Inject sumatriptan just under the skin, in the side of your thigh or your upper arm. The thigh is usually preferred. The following video is a guide.

Precautions – before taking sumatriptan

Do you have problems with your liver or kidneys?
Do you have problems with high blood pressure (hypertension)?
Have you had a heart attack or do you get angina (chest pain)?
Have you had a stroke or do you get transient ischemic attacks?
Are you pregnant?
Are you breastfeeding?
Are you taking medicine for depression?

If so, it’s important that you tell your doctor or pharmacist before you start sumatriptan. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Side effects

Like all medicines, sumatriptan can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects	What should I do?
Feeling sleepy, Dizziness Tiredness	Be careful when driving or using tools until you know how this medicine affects you. Do not drink alcohol.
Feeling sick or vomiting	This may be due to the migraine attack. Avoid eating until this feeling passes. Tell your doctor if this is troublesome.
Pain, or tightness in your chest, jaw or throat	If the pain is intense or does not go away tell your doctor immediately or phone Healthline 0800 611 116.
Pain, or redness at the injection site	Change the injection site. Tell your doctor if troublesome.
Signs of serotonin syndrome such as feeling agitated and restless, heavy sweating, shivering, fast heart rate or irregular heartbeat, headache, diarrhoea (runny poos) and rigid or twitching muscles	You are at increased risk of serotonin syndrome if you recently started taking sumatriptan, recently increased the dose or if you are taking other medicines that can cause serotonin syndrome. Tell your doctor immediately or phone Healthline 0800 611 116.

Interactions

Sumatriptan may interact with a few medications and herbal supplements, so check with your doctor or pharmacist before starting sumatriptan or before starting any new medicines. It may also interact with some cold and flu preparations containing dextromethorphan such as Benadryl®