Serotonin Syndrome: An Emerging Reality in the Emergency Department

Serotonin syndrome (SS) is an entity caused by interference with the serotonin metabolism and/or by medications that act as serotonin receptor agonists. The signs and symptoms are nonspecific, making the diagnosis challenging. Treatment depends on the severity of the manifestations. In mild to moderate cases, it typically resolves within the first 24 hours after initiating therapy and discontinuation of the serotoninergic medications. A 42-year-old woman with a previous history of depression was admitted to the hospital due to the voluntary ingestion of multiple tablets of escitalopram 10 mg and venlafaxine 75 mg. Physical examination showed a hyperthermic and diaphoretic patient. Tremor, agitation, bilateral ocular clonus, and spontaneous inferior limb clonus were also present. Hunter's criteria were applied, and the diagnosis of SS was assumed. Supportive and symptomatic treatments were initiated. The evolution was benign, with symptomatic remission in the first 24 hours. In the last decades, a large increase in the use of antidepressants was noted, and, as such, defining SS as rare is no longer appropriate. Delaying the treatment can dictate an increase in morbidity and mortality. It is important to highlight that the diagnosis is mainly clinical as diagnostic criteria may miss out on some cases. As such, clinical awareness of SS's multiplicity of presentations is of utmost importance.