A case report of suspected serotonin syndrome following administration of fentanyl

Background: Serotonin syndrome (SS) is a potentially life-threatening drug-induced toxidrome that can occur because of an overdose of a serotoninergic drug or the combination of multiple drugs with serotoninergic activity at therapeutic doses, leading to an increase in serotonergic activity in the central and peripheral nervous system. SS in the setting of general anesthesia is uncommon but possibly underdiagnosed because of the variability in its severity and symptomatology. This report presents a case of severe SS following the administration of fentanyl during induction of general anesthesia. Additionally, it provides a brief overview of the pathophysiology, clinical features, management strategies, and commonly used drugs by anesthesiologists that can potentially result in a fatal interaction.