Sumatriptan (Imitrex) warnings: what you need to know

Yael Cooperman, MD - Contributor Avatar

Reviewed by Yael Cooperman, MD, Ro, 

Written by Hana Dethlefsen 

Yael Cooperman, MD - Contributor Avatar

Reviewed by Yael Cooperman, MD, Ro, 

Written by Hana Dethlefsen 

last updated: Sep 21, 2020

6 min read

Sumatriptan (brand name Imitrex) is a drug commonly prescribed for moderate to severe migraines and cluster headaches (Smith, 2020). If this is you, you’re looking for effective and safe pain relief, and sumatriptan may help you get back to your usual self. Sumatriptan is effective and generally well-tolerated. Research shows that serious side effects are relatively rare (Perry, 1998).

There are some patients for whom sumatriptan isn’t the right choice. Sumatriptan works in part by constricting blood vessels, so it may not be suitable for patients with the following conditions: CAD (coronary artery disease), TIA (transient ischemic attacks), hypertension, vasospasms, Prinzmetal angina, or history of heart attack or uncontrolled high blood pressure. If you have any of these or related conditions, your healthcare provider may find you an alternative treatment for migraine (FDA, 2013).

This article will walk you through the most important sumatriptan warnings and side effects and outline which patients would benefit from alternative treatments. You should be able to take your medication safely and confidently, and we hope this article helps.


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How does Imitrex work?

The drug information label is easier to understand if you know a little bit about sumatriptan and how it works. Sumatriptan is part of a group of drugs called triptans. They work like serotonin, a chemical that your body naturally produces to send signals between nerve cells. Although researchers are still figuring out exactly why triptans work, they do know that they do two things: constrict the blood vessels in the brain and stop certain pain signals in the brain (Ahn, 2005). 

What does the sumatriptan warnings label mean?

Reading the warnings section of any medication label can be alarming. Here’s a run-down of the most important warnings on the sumatriptan label so you can better understand what they mean for you and your health and to avoid any adverse effects (FDA, 2013). 

Heart and blood vessel warnings

Some of the warnings on the label are there because sumatriptan works by constricting blood vessels (Ahn, 2005). The below warnings have to do with this effect of the drug (FDA, 2013): 

  • Heart problems: Sumatriptan works by constricting blood vessels, so it may not be suitable for people with heart conditions. Sumatriptan can worsen coronary artery disease (ischemia) or provoke a heart attack (myocardial infarction) or Printzmetal’s angina (coronary artery vasospasm). It can also cause irregular heart rhythms.

  • Chest, neck, jaw, throat tightness: Sumatriptan, in some cases, has been shown to cause chest pain or a heavy feeling, pressure, or tightness in the chest, neck, jaw, or throat. Note that these can also be signs of a heart attack. If you experience these symptoms, especially if they are accompanied by nausea or vomiting, or if you have a history of coronary artery disease (heart attacks, angina), seek medical attention immediately. 

  • High blood pressure: Constricting blood vessels can lead to a sudden increased blood pressure called hypertensive crisis, affecting organ function. Symptoms of a hypertensive crisis include a sudden pounding headache, nausea, vomiting, chest pain, dizziness, loss of consciousness, and difficulty breathing. If you experience any of these symptoms, seek immediate medical attention. 

  • Ergotamines: you should not take sumatriptan within 24 hours of using ergotamines or other ergot-type medications. Together, these medications can cause excessive narrowing of the blood vessels, which can reduce blood flow to certain organs in the body (Worthington, 2013).

Serotonin syndrome

Sumatriptan and other triptan medications cannot be combined with other serotonin-like medications. This is because taking too much sumatriptan or combining it with other serotonin-like drugs can cause serotonin syndrome, which can be fatal if not treated (FDA, 2013). Symptoms include vomiting, diarrhea, high blood pressure, shaking/tremors, sweating, a fast heartbeat, and feeling disoriented, restless, or anxious (Heller, 2018).

Inform your healthcare provider of all medications you take, whether you take them daily or periodically, in order to avoid drug interactions with other serotonin-like medications. These include (NIH, 2015):

  • SSRIs (selective serotonin reuptake inhibitors) like Celexa or Lexapro

  • SNRIs (selective serotonin/norepinephrine reuptake inhibitors) like Cymbalta and Effexor

  • MAOIs (monoamine oxidase inhibitors) like Nardil

  • Medications for the treatment of Parkinson’s disease

Other warnings

  • Allergy: Do not take sumatriptan if you have an allergy to it or any other ingredients within the medication. In susceptible people, this medication can cause a severe allergic reaction that can restrict breathing and can be deadly without treatment (FDA, 2013). Ensure your healthcare provider is aware of any previous allergic reactions or hypersensitivities you’ve had to medications in the past and do not use this medication if you develop an allergy.

  • Seizure: There have been reports that sumatriptan can increase a person’s chance of experiencing a seizure, especially if they have experienced seizures in the past. Let your healthcare provider know if you have a personal or family history of seizures. (FDA, 2013).

  • Liver disease: Sumatriptan is processed in the liver, and liver disease changes your body’s ability to process the medication. People with a history of liver disease may require a lower dose (FDA, 2013). 

What are the contraindications to using sumatriptan?

Taking sumatriptan if you have certain medical conditions can be dangerous. Let your healthcare provider know if you have liver disease or if you’ve ever had an allergic reaction to sumatriptan or any other triptan drug if you have heart problems such as coronary artery disease, Prinzmetal angina, irregular heart rhythms, Wolff-Parkinson-White syndrome, or any history of heart disease.

  • Vascular conditions like uncontrolled high blood pressure, ischemic bowel disease, or peripheral vascular ischemia

  • A history of seizures or epilepsy 

  • A history of a stroke or TIA (transient ischemic attack) (FDA, 2013)

Is sumatriptan succinate a narcotic?

Sumatriptan isn’t a narcotic. While it’s been proven to alleviate the pain associated with migraines, it won’t alleviate other pain or give you a “high” sometimes associated with narcotics. Sumatriptan is part of a group of medications called triptans, drugs that act like serotonin and work to alleviate migraine headaches when taken at their onset. (Other triptans include eletriptan, frovatriptan, and naratriptan.) Narcotics (such as codeine and fentanyl) are part of a group of drugs called opioids, and sumatriptan isn’t one (Vorvick, 2019).

Narcotic treatment can be risky because of its habit-forming qualities, so doctors will typically try other medications first. Sumatriptan is more effective in relieving migraine headaches than narcotics, but if triptan treatment doesn’t work, your healthcare provider may consider prescribing narcotics to help alleviate your pain (Worthington, 2013).

What is Imitrex, and what is the right dosage? 

Sumatriptan stops a migraine attack or cluster headache from getting worse, so it’s most effective when taken early (Worthington, 2013). It’s not a drug you take to prevent attacks, but one you take once it starts, which is why it’s called a “rescue drug.” 

Sumatriptan can be taken in one of three ways, as a tablet by mouth, as a nasal spray, or as a self-administered injection under the skin (NIH, 2019a). Research shows that for some patients, a combination of sumatriptan with an NSAID medication (like naproxen) is more effective at relieving migraines (Worthington, 2013). This drug combination is available by prescription and contains both sumatriptan and the pain reliever naproxen (e.g., brand name Treximet) (NIH, 2015). 

Depending on which brand you’re taking and the method of administration, the doses will vary. 

  • Oral sumatriptan tablets come in 50 mg or 100 mg doses. Although 100 mg doses may be more effective, patients taking 50 mg doses experienced fewer side effects. 200 mg is the maximum dose for a 24 hour period (Derry, 2014).

  • Subcutaneous sumatriptan injections are usually 6 mg. 12 mg is the maximum dose in any 24 hour period (FDA, 2019a). 

  • Intranasal sumatriptan doses range from 5mg per dose to 10 mg to 22 mg, depending on the exact medication (FDA, 2017; FDA, 2019b; FDA, 2016). See your medication label for specific instructions.

Using sumatriptan (or other migraine headache medications like ergotamines or opioids) more than ten times per month can lead to medication overuse headaches (MOH) or “rebound headaches” (FDA, 2013). 

Sumatriptan/Imitrex side effects

The most common side effect of sumatriptan is drowsiness (NIH, 2015). Don’t drive or operate heavy machinery when taking sumatriptan (FDA, 2013). Other side effects may vary based on the route of administration.

If you take the oral sumatriptan tablet, you might feel sleepy, weak, dizzy, or have an upset stomach or diarrhea. You may also experience hot or cold flashes, a tingling sensation, or get muscle cramps (NIH, 2015). 

If you are taking nasal sumatriptan, the most common side effect is an unpleasant taste (Smith, 2020). You could also get a sore throat or irritation, or a tingling sensation in your nose. Other possible side effects include nausea, a pounding or irregular heartbeat, and flushing (NIH, 2019b). 

For self-injections, some side effects include redness, tingling, a warm feeling, or irritation at the injection site. You may also experience an upset stomach, vomiting, or muscle cramps (NIH, 2017). 

Other possible side effects could be more serious. Seek medical attention immediately if you have chest pains or tightness in the throat, neck, jaw, or chest, a fast or pounding heartbeat, shortness of breath, or difficulty talking. While these side effects may be caused by sumatriptan, they can also be symptoms of a heart attack (NIH, 2015; FDA, 2013). 


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

September 21, 2020

Written by

Hana Dethlefsen

Fact checked by

Yael Cooperman, MD

About the medical reviewer

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.