Serotonin Syndrome

Serotonin syndrome is a potentially life-threatening drug reaction that results from having too much serotonin in your body. Serotonin is a neurotransmitter, a chemical produced by nerve cells in your brain and other areas of your body.

Most people can safely take serotonin-affecting (serotonergic) medication when it’s prescribed at the appropriate dosage and under the guidance of their healthcare provider. Serotonin syndrome happens most often when you either take a new drug or take an increased dose of a drug that increases the level of serotonin in your body. If your body processes serotonin differently or it can’t process an increased amount of serotonin, serotonin syndrome symptoms can happen.

Serotonin syndrome can cause mild symptoms (like diarrhea or nausea) to severe symptoms (like high fever or seizures). In some cases, severe serotonin syndrome can be fatal if not recognized and treated quickly.

Healthcare providers first recognized serotonin syndrome in the 1960s, after the approval of the first antidepressant medications. Today, more serotonin-affecting medications are available. This has led to a growing number of cases of serotonin syndrome.

Who gets serotonin syndrome?

Anyone who takes certain prescription medications, over-the-counter drugs, herbal or dietary supplements and illegal drugs that affect their body’s serotonin levels could be at risk for serotonin syndrome. It happens to people of any age.