Serotonin syndrome: An often-neglected medical emergency

Abstract

Optimum serotonin level in the serotonergic synapses of the central nervous system (CNS) is related to mood, behavior, and sleep. Serotonin syndrome (SS) is a rare yet very dangerous adverse effect resulting from increased serotonin in CNS. The diagnosis of SS is based on the presence of clinical symptoms, which can include agitation, confusion, rapid heart rate, high blood pressure, dilated pupils, muscle rigidity, tremors, sweating, and diarrhea. SS is invariably caused by inadvertent use of serotonergic medicines. There is an ever-growing list of medicines that are associated with the risk of SS. Some of the common classes of drugs that can contribute to the development of SS include selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, monoamine oxidase inhibitors, tricyclic antidepressants, stimulants (e.g., amphetamines and cocaine), lithium, opioids, drugs used for recreational purposes like ecstasy Methylenedioxymethamphetamine (MDMA), and some herbal supplements (e.g., St. John's Wort). SS can occur when these medications are taken alone or in combination, especially when a new medication is added, or the dose of an existing medication is changed. The management of SS typically involves discontinuing the use of the substance that caused the excess serotonin levels and providing supportive care, such as intravenous fluids and electrolytes. In severe cases, benzodiazepines may be used to control agitation and muscle rigidity, while serotonin antagonists, such as cyproheptadine, may be used to reduce serotonin levels. The literature review points to a general unawareness among physicians about the condition or drugs associated with it. Consequently, this potentially fatal condition is overlooked. There is a need for regular information updates and reminders to all those who prescribe medications to the patients.

Keywords: Selective serotonin reuptake inhibitors; serotonin; serotonin syndrome.

Figure 1

Conditions mimicking serotonin syndrome

Figure 2

Hunter’s criteria for diagnosis of serotonin syndrome