A perfect storm in the emergency department

Background Serotonin syndrome is an iatrogenic disorder that results from serotonergic overactivity. Severe myoc- lonus and increased restlessness are hallmarks of the disorder. Methods We report a case of serotonin syndrome related to poor drug elimination. Results A 74-year-old white female with moderate to severe Alzheimer's dementia was brought to the emergency department for increasingly aggressive behavior. Upon admission, her risperidone dose was increased and citalopram continued. Several days later, she developed diffuse limb and facial myoclonus, spontaneous clonus, diaphoresis, and fever. Her symptoms completely resolved after discontinuation of these medications. Conclusion Serotonin syndrome should be considered in the differential when elderly patients present with severe myoclonus. If unrecognized, this syndrome can lead to more severe manifestations including rhabdomyolysis, renal failure, and coma.