Sumatriptan (injection)

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 to 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, do not take another sumatriptan dose for this same attack. It is unlikely to work.

Monthly limit

Do not use sumatriptan for more than 10 days per month. 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 to 10 days after sumatriptan has been stopped. Symptoms may be worse before an improvement is seen. To avoid this, do not use sumatriptan for more than 10 days per month.

How to take sumatriptan

• Use sumatriptan injection as soon as you notice headache symptoms, or after a migraine has already begun.
• Sumatriptan injection usually starts to work within 10 to 15 minutes after the injection is given.
• Inject sumatriptan just under the skin only using the sumatriptan auto-injector device. Ask your doctor, nurse or pharmacist to show you how to use it.
• You can inject yourself in the side of your thigh, or the upper arm.

Precautions – before taking sumatriptan

If you answer 'yes' to any of the following questions, it’s important that you tell your doctor or pharmacist 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 medication for depression?

Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Possible 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.

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®

Learn more

The following links have more information on sumatriptan.

New Zealand Formulary: Sumatriptan 
Medsafe Consumer Information Sheet: Imigran injection

References

1. Treatment of acute migraine New Zealand Formulary
2. Diagnosing and managing headache in adults in primary care BPAC, 2017 
3. The role of triptans in the treatment of migraine in adults BPAC, 2014