Serotonin syndrome

Serotonin Syndrome (SS) is a potentially life-threatening condition triggered by an excess of serotonin, a chemical produced by nerve cells, within the central nervous system. This excess can be a consequence of medication use, particularly when drugs that affect serotonin levels are taken together. The condition encompasses a range of symptoms that can appear rapidly and vary from mild to severe.

SS is characterized by a triad of abnormalities: cognitive changes such as confusion and agitation; autonomic instability, including fever and changes in blood pressure; and neuromuscular anomalies like tremors and reflex changes. The most common contributing medications include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), and other drugs that influence serotonin metabolism or function.

Diagnosis is clinical, largely based on the patient's history and presenting symptoms, often employing criteria such as the Hunter Serotonin Toxicity Criteria, which emphasizes the presence of clonus — a series of involuntary muscle contractions and relaxations. Treatment primarily involves stopping the serotonergic medication and providing supportive care to stabilize the patient.

Due to the variety of drugs implicated and the range of presenting symptoms, SS can be challenging to diagnose. It requires a high index of...