Serotonin Syndrome Patient Information

Serotonin syndrome is a potentially fatal drug reaction that occurs when too much of the chemical serotonin accumulates in the body. To keep yourself safe from the dangers of too much serotonin, it is important to be aware of what causes serotonin syndrome to occur, how it manifests, how it is treated, and how it can be prevented.

The Function of Serotonin

• Your brain, spinal cord and intestines have nerve cells that produce serotonin, a chemical that helps regulate your body temperature, your behavior, your attention, your respiration, digestion and your blood flow. While serotonin is indeed an important chemical that is naturally produced by your body, having too much of it can be detrimental.

Symptoms

• The following symptoms of serotonin syndrome may occur between minutes and hours: agitation or restlessness; confusion; diarrhea; rapid heart beat/pulse; dilated pupils; hallucinations; anxiety; headache; increased body temperature; loss of coordination; nausea and/or vomiting; overactive reflexes; and rapid blood pressure changes.

  Symptoms of severe serotonin syndrome may be fatal. These include: seizures; high fever; irregular heartbeat; and loss of consciousness.

Causes

• Serotonin syndrome can occur when you start a new drug, increase the dose of a drug, or add a new drug to the list of drugs you are already taking. The following drugs are often responsible for causing serotonin syndrome: antidepressants such as SSRIs, SNRIs, MAOIs and tricyclics, anti-migraine medications, herbal supplements, pain medications, anti-nausea medications and some over-the-counter cough/cold medications containing dextromethorphan. There are also some illicit drugs, including LSD, cocaine and ecstasy, that can cause serotonin syndrome.

Diagnosis

• There is no one test that can diagnose serotonin syndrome. A physician will likely deduce that you have serotonin syndrome by ruling out other possibilities. He will also ask you about your medical history, including medications you may be taking. He may also perform tests, including a thyroid test, a drug level test and a test which checks body functions that may be affected by high concentrations of serotonin in your body.

Treatments

• The way serotonin syndrome is treated depends on the severity of the condition. A physician may conclude that minor symptoms will cease if you stop taking the medication that has triggered them. Stronger symptoms that concern your physician may mean a hospital stay and/or additional treatments such as muscle relaxant medication, serotonin-production blocking agents, blood pressure medication, intravenous fluids and supplemental oxygen.

Prevention

• You are at higher risk of suffering from serotonin syndrome if you take more than the prescribed dose of an anti-depressant, notably an SSRI or SNRI. If you are concerned about your current dose, do not stop taking the medication but discuss your options with your physician. Also, before a doctor prescribes you a new medication, it is imperative that you inform your doctor about any medications you are already taking. Your doctor may believe that you need to take two medications simultaneously despite the higher serotonin syndrome risk. Therefore, be extra aware of potential serotonin symptoms.