Imitrex (sumatriptan) is a prescription brand-name medication. The Food and Drug Administration (FDA) has approved it to treat migraine with or without aura. Imitrex is available in injection, tablet, and nasal spray forms. The injection forms are also approved to treat cluster headaches.
It’s important to note that Imitrex is not approved to help prevent migraine or cluster headaches.
The active drug in Imitrex is sumatriptan. And Imitrex is available as the generic drug sumatriptan. Imitrex is in a drug class known as serotonin agonists (triptans).
For information about the dosages of Imitrex, including its forms, strengths, and how to use the medication, keep reading. For a comprehensive look at Imitrex, see this article.
This article describes typical dosages for Imitrex provided by the drug’s manufacturer. When using Imitrex, always follow the dosage prescribed by your doctor.
Imitrex is available in several different forms and strengths, which are described below. The form and strength your doctor prescribes will determine the dosage of Imitrex you use.
Imitrex forms
Imitrex comes in these forms:
- liquid solution given as a subcutaneous injection with either:
- STATdose pen and prefilled cartridge
- single-dose vial for use with a syringe
- oral tablets
- nasal spray
Imitrex strengths
The forms of Imitrex are available in the strengths listed below. Milligrams and milliliters are abbreviated as mg and ml.
| Oral tablet | Nasal spray | STATdose pen | Single-dose vial |
| 25 mg | 5 mg | 4 mg/0.5 ml | 6 mg/0.5 ml |
| 50 mg | 20 mg | 6 mg/0.5 ml | |
| 100 mg |
Typical dosages
Typically, your doctor will start you on a low dosage. Then they’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.
The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.
Dosage for migraine
The Imitrex dosage for migraine with or without aura depends on which form of Imitrex your doctor prescribes.
Oral tablet dosage
For treating migraine, Imitrex oral tablets (pills) can be given in a dose of 25 mg, 50 mg, or 100 mg. You should take your dose when you first feel symptoms of migraine, but you may take a dose at any time during the migraine.
If the first dose doesn’t fully relieve your migraine episode, you may take a second dose. But you should wait at least 2 hours after your first dose before taking another dose.
Nasal spray dosage
For treating migraine, Imitrex nasal spray may be prescribed in doses of 5 mg, 10 mg, or 20 mg. The 5-mg and 20-mg doses require a single spray in one nostril. The 10-mg dose requires one spray of the 5-mg dose in each nostril.
If the first dose doesn’t fully relieve your migraine episode, you may take a second dose. But you should wait at least 2 hours after your first dose before taking another dose.
STATdose pen and vial dosage
For treating migraine, the recommended starting dose with the STATdose pen or vial is a single dose of 6 mg. If side effects from this strength are bothersome, your doctor may switch you to a lower dose of 1 mg to 5 mg. (For more about side effects of Imitrex, see this article.)
The STATdose pen uses prefilled single-dose cartridges, so it can only provide 4-mg or 6-mg doses. For other prescribed doses, you’ll need to use the single-dose vial.
If the first dose doesn’t fully relieve your migraine episode, you may take a second dose. But you should wait at least 2 hours after your first dose before taking another dose.
Dosage for cluster headaches
Only the injection forms of Imitrex are approved to treat cluster headaches. These forms are the STATdose pen and vial. You can find the dosages below.
STATdose pen and vial dosage
For treating cluster headaches, the recommended dose with the STATdose pen or vial is 6 mg.
If the first dose doesn’t fully relieve your cluster headache, you may take a second dose. But you should wait at least 2 hours after your first dose before taking another dose.
Maximum dosage
The maximum Imitrex dosage per day depends on the form of Imitrex you use:
- oral tablet: 200 mg over 24 hours
- nasal spray: 40 mg over 24 hours
- STATdose pen or vial: 12 mg over 24 hours
Long-term use
Imitrex is meant to be used as a long-term treatment. If you and your doctor determine that Imitrex is safe and effective for you, you’ll likely use it long term.
Below are answers to some frequently asked questions about Imitrex dosages.
What’s the maximum dosage of Imitrex per month?
It’s not known whether it’s safe to use Imitrex to treat more than four headaches per month (30 days). Your doctor can give you more information about using Imitrex safely to treat migraine or cluster headaches.
If you’d like to know more about the maximum daily doses of Imitrex, see “Maximum dosage” in the “Imitrex dosage” section above.
Why don’t the pill or nasal spray forms of Imitrex treat cluster headaches?
Imitrex’s pill and nasal spray forms haven’t been proven to be safe and effective for treating cluster headaches. That’s why these forms aren’t approved to treat the condition.
Only the injection forms of Imitrex have been shown, through clinical studies, to be safe and effective for treating cluster headaches.
Talk with your doctor if you’d like to learn more about Imitrex or other cluster headache treatments.
Find the dosing instructions for how to use each form of Imitrex below.
Dosing instructions for oral tablets
You’ll take Imitrex oral tablets by mouth. When you notice migraine symptoms, you’ll swallow one pill whole with water or another liquid.
Dosing instructions for nasal spray
For Imitrex nasal spray, you’ll insert the unit (disposable device) in one nostril and spray one time. To view step-by-step instructions for using Imitrex nasal spray, see the drug’s instructions for use.
Dosing instructions for STATdose pen or vial
Instructions for using the STATdose pen and vial differ slightly. Your doctor or another healthcare professional can show you how to use either form properly.
To use the STATdose pen, you’ll load the device with a cartridge. You’ll then give yourself a dose by subcutaneous injection. Your doctor will tell you where on your body to inject your doses. Make sure you hold the pen against your skin for at least 5 seconds when injecting a dose. To view step-by-step instructions for using the pen, refer to the drug’s instructions for use.
To use the single-dose vial, you’ll use a syringe and needle to draw up your dose from the vial. Your doctor or a healthcare professional will give you instructions about how much Imitrex to use. They’ll also tell you where on your body to inject doses.
The Imitrex dosage your doctor prescribes will depend on several factors. These include:
- the type and severity of the condition you’re using Imitrex to treat
- the form of Imitrex you use
- side effects* that you experience from using Imitrex
Other medical conditions you have can also affect your Imitrex dosage.
* For more about side effects of Imitrex, see this article.
Dosage adjustments
If your doctor prescribes Imitrex oral tablets and you have liver problems, they may adjust your dosage. You can talk with your doctor to learn more.
Also, if you’re age 65 years or older, you may be given a lower starting dose of Imitrex than usual. This is so your doctor can see how the medication affects you. Older adults may have an increased risk of side effects from Imitrex. Your doctor can give you more information.
Imitrex isn’t a medication you take every day. Because you use the medication only as needed when you have a cluster headache or migraine, you can’t miss a dose.
It’s best to take a dose of Imitrex as soon as your symptoms start. But you can take a dose at any time during a migraine or cluster headache.
It’s important that you don’t use more Imitrex than your doctor prescribes. For some medications, taking more than the recommended amount may lead to side effects or overdose.
If you take more than the recommended amount of Imitrex
Call your doctor right away if you believe you’ve taken too much of Imitrex. Another option is to call the American Association of Poison Control Centers at 800-222-1222 or use its online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.
The dosages in this article are typical dosages provided by the drug manufacturer. If your doctor recommends Imitrex for you, they will prescribe the dosage that’s right for you. Always follow the dosage that your doctor prescribes for you.
As with any drug, never change your dosage of Imitrex without your doctor’s recommendation. If you have questions about the dosage of Imitrex that’s right for you, talk with your doctor.
Besides learning about dosage, you may want other information about Imitrex. These additional articles might be helpful to you:
- More about Imitrex. For information about other aspects of Imitrex, refer to this article.
- Side effects. To learn about side effects of Imitrex, see this article. You can also look at the Imitrex prescribing information for the form of the medication you’re using: STATdose pen or vial, tablets, or nasal spray.
- Drug comparison. To find out how Imitrex compares with Maxalt, refer to this article. To learn about the similarities and differences between Imitrex and Relpax, see this article.
- Details about your condition. For details about cluster headaches and migraine, see our headache and migraine hub. You can also refer to our list of related articles.
Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
