Ocular Flutter in the Serotonin Syndrome A 46-year-old woman was brought to the emergency department because of agitation. On arrival, she had a fever (temperature, 38.6°C) and tachycardia (heart rate, 169 beats per minute). The patient was agitated and had ocular flutter (Video 1) as well as rigidity in the legs and myoclonus in the arms (Video 2). The bowel sounds were hyperactive, and her skin was cold, with diaphoresis. Her medications included benzodiazepines (alprazolam and estazolam) and venlafaxine (a serotonin–norepinephrine reuptake inhibitor that is typically prescribed for major depressive disorder and generalized anxiety disorder). She reported taking more doses of venlafaxine than were prescribed. Her symptoms and medication history suggested the serotonin syndrome. The patient was given midazolam and was intubated for airway protection. The myoclonus and autonomic hyperactivity abated after the injection of midazolam, but the ocular flutter persisted. The serotonin syndrome may be life-threatening. The typical clinical manifestations include changes in mental status, autonomic instability, and neuromuscular findings such as myoclonus, ocular flutter, muscular rigidity, and hyperreflexia. The patient was admitted to the intensive care unit and died several days later.
How did the overdose of venlafaxine cos the syndrome, seeing that the drug inhibits uptake of serotonin?
It's a REuptake inhibitor. It prevents the body from breaking down any excess serotonin which basically just causes an overflow.