Can Imitrex (sumatriptan) cause serotonin syndrome?

While serotonin syndrome can occur from taking Imitrex (sumatriptan) by itself, the risk is higher if you take it with other medications that can affect serotonin. Serotonin is a chemical in the brain that affects mood and behavior. Too much serotonin activity in the brain can lead to toxicity and serious side effects.

You should stop taking Imitrex and get medical attention right away if you believe you have symptoms of serotonin syndrome.

What are the symptoms of serotonin syndrome?

Symptoms of serotonin syndrome usually occur within minutes or hours of taking a new or higher dose of a medication that can affect serotonin levels. You may experience mild symptoms, or they could become life-threatening.

If you have serotonin syndrome, you may experience some of the following symptoms:

• Agitation
• Diarrhea
• Fever
• Rapid heartbeat
• Hallucinations
• High blood pressure
• Nausea or vomiting
• Confusion
• Muscle spasms
• Shivering
• Trouble walking

These are not all possible signs and symptoms of serotonin syndrome. If you think you are experiencing serotonin syndrome, get medical help right away.

What medications can raise the risk of serotonin syndrome?

Medications that have been associated with serotonin syndrome, especially when combined, include:

• Dextromethorphan
• Opioids
• Lithium
• Selective serotonin reuptake inhibitors (SSRIs)
• Serotonin and norepinephrine reuptake inhibitors (SNRIs)
• St. John’s wort
• Triptans
• Tricyclic Antidepressants (TCAs)
• Monoamine oxidase inhibitors (MAOIs)

Other medications may cause serotonin syndrome, and the list above is not all-inclusive. Check with your healthcare provider each time you start a new medication. They can review your individual risk for serotonin syndrome with you.

How common is serotonin syndrome from Imitrex?

Serotonin syndrome while taking Imitrex is rare, especially if you are not taking other medications that affect serotonin. There currently is not enough information to know how common serotonin syndrome is from taking Imitrex (a triptan) alone or combined with other serotonergic medications. The information available is based on case reports.

Each year, it is estimated that about 5 to 7 cases of serotonin syndrome associated with triptan therapy are reported to the FDA. This includes patients taking a triptan alone and in combination with other medications that affect serotonin.

As of 2010, the FDA has identified 11 cases of serotonin syndrome in patients taking a triptan medication by itself.

One study looked at health records of about 19,000 patients who were prescribed triptans and an SSRI or SNRI antidepressant. Researchers found that serotonin syndrome was suspected in 17 patients, and only 2 patients had definite serotonin syndrome. Keep in mind that the more medications you take that affect serotonin, the higher your risk gets for serotonin syndrome.