Serotonin toxicity: pre-hospital recognition and management

Abstract

Serotonin toxicity is a preventable, potentially serious condition caused by an increase in the neurotransmitter serotonin. The condition can produce a wide variety of symptoms ranging from mild to life threatening. Common signs of severe life threatening toxicity include clonus, myoclonus, hyperreflexia, muscle rigidity and hyperthermia. Serotonin toxicity is caused by taking one or more serotonergic agents which are responsible for raising intrasynaptic serotonin to an abnormally high level. Severe and fatal toxicity are usually associated with taking two different serotonergic agents with different pharmacological actions such as selective serotonin reuptake inhibitors (SSRIs) and monoamine oxidase inhibitors (MAOIs). There is no specific pre-hospital treatment for serotonin toxicity. It is based mainly on patients presenting signs and symptoms. The cessation of any serotonergic agents will normally resolve symptoms within 24 hours. Unfortunately it is a condition still not widely recognised by health care professionals (HCP), therefore it is important pre-hospital clinicians are aware of the clinical features of the condition and how best to manage them.