Migraine Medications May Cause 'Serotonin Syndrome'

May 15 -- WEDNESDAY, May 14 (HealthDay News) -- A commonly used migraine medication may cause so-called serotonin syndrome in rare cases, new research suggests.

Reporting in the May 15 issue of the New England Journal of Medicine, researchers from Georgetown University and the U.S. Food and Drug Administration detail 11 cases of serotonin syndrome associated with the use of triptans alone that were reported to the FDA's Adverse Event Reporting System (AERS).

"The FDA has already issued an advisory and an alert that when triptans are used in combination with SSRIs, there is a possibility of serotonin syndrome. The news here is that it doesn't have to be in combination, triptans alone can cause serotonin syndrome," said the study's lead author, Offie Soldin, an associate professor of medicine and oncology at Georgetown University Medical Center.

Serotonin syndrome occurs when there is too much of the neurotransmitter serotonin, often because more than one medication that affects serotonin levels has been taken, according to the U.S. National Institutes of Health (NIH). Symptoms of serotonin syndrome include mental status changes, overactive reflexes, muscle spasms, fever, uncoordinated movements, heavy sweating and nausea or vomiting.

People with migraine headaches may be especially at risk, because medications taken to prevent migraines from occurring -- such as Zoloft, Paxil, Lexapro and Prozac -- are from a class of medications known as selective serotonin reuptake inhibitors (SSRIs), and they make serotonin more available in brain cells, called neurons. Additionally, the medications used to treat an oncoming or active migraine, such as Imitrex, Zomig, Frova, Maxalt and Axert, are from a class of medications known as triptans, which are selective serotonin receptor agonists, and can also make serotonin more available in your body. Other medications, such as older antidepressants, can also increase the levels of serotonin.

Serotonin syndrome is most likely to occur when you've just started serotonin-altering medications, according to the NIH.