What is Serotonergic Syndrome?

Serotonergic syndrome, also called serotonin syndrome or hyperserotonemia, is a condition that occurs when a patient takes two or more certain types of drugs at the same time. These drugs increase the amount of serotonin in the brain, which is a naturally-produced chemical used by the nervous system. Patients who experience this medical condition must seek emergency medical help. Severe cases of serotonergic syndrome may be fatal if they are not treated promptly.

Sometimes, symptoms of serotonergic syndrome can occur within minutes of taking the drugs, or it may take several hours. These symptoms can include agitation, rapid heartbeat, and dilated pupils, as well as goose bumps, shivering, and sweating. The muscles may twitch involuntarily and the patient may also experience confusion, headache, and diarrhea. Patients with severe serotonergic syndrome can also lose consciousness, have a seizure, or suffer from a high fever. If any of these symptoms occur after taking certain drugs, patients must go to the emergency room immediately, even if the symptoms initially appear mild.

While serotonin is a substance that is naturally produced by the body, the body alone cannot manufacture enough of this chemical to lead to serotonergic syndrome. This condition may be caused by either taking too many drugs, or by taking an excessively high dose of one drug. There are many different medications that can increase serotonin, such as antidepressants, selective serotonin reuptake inhibitors (SSRIs), and drugs for migraines and pain. Over-the-counter drugs and supplements can also increase serotonin, such as cough medicine, ginseng, and St. John's wort. Some recreational drugs have the same effect, including cocaine, amphetamines, and Ecstasy.

When a patient is suspected of having serotonergic syndrome, it is helpful for him to disclose all of the drugs and supplements he had recently taken. To rule out the possibility of other medical conditions, the doctor must run a battery of tests, including a complete blood count (CBC), a blood culture test, and a toxicology screen. He will also likely order tests to check for liver, kidney, and thyroid function, as well as an evaluation of the patient's electrolyte levels.

Treatment for serotonergic syndrome begins with discontinuing the medications that led to this condition. It is likely that the patient will remain in the hospital for several hours to a full day for observation and treatment. Cyproheptadine may be administered, which is a drug that prevents the body from manufacturing more serotonin. Patients may also be prescribed medication to control symptoms, such as benzodiazepines.

If the patient experiences very severe muscle spasms, this could lead to muscle breakdown and kidney damage. In these potentially life-threatening cases, the doctor will temporarily paralyze the patient with medications. He will be hooked up to a breathing machine while he recovers. Severe incidences of serotonergic syndrome may not be completely resolved for a few weeks, while patients with mild cases will recover in about 24 hours.