C-Reactive Protein and Serotonin Syndrome

Mr. A was a 53-year-old hypertensive man who was hospitalized for depression. Mr. A was given a prescription for fluoxetine; his outpatient psychotropics—clonazepam, tramadol, and trazodone—were continued. On hospital day 6, Mr. A became acutely confused and had visual hallucinations, gastrointestinal distress, fever, tachycardia, edema, and a fine petechial rash of the lower extremities. Infection or vasculitis was considered, given the rash and abdominal symptoms. A computerized tomography scan of his head, magnetic resonance imaging, and magnetic resonance angiography were negative for a cerebrovascular accident and vasculitis. An EEG twice gave normal results. Other normal laboratory results included a lumbar puncture, two negative qualitative serum antinuclear antibody levels, a cardiac enzyme level, a CBC, comprehensive serum chemistries, and coagulation studies. However, Mr. A’s C-reactive protein was elevated, at 19.2 mg/dl (normal=0 to 0.6 mg/dl). Serotonin syndrome was diagnosed, with symptoms consistent with this and multiple medications with serotonergic activity. Fluoxetine, tramadol, and trazodone were discontinued, and the serotonergic blocker cyproheptadine was begun. By hospital day 22, free of symptoms of serotonin syndrome, Mr. A’s C-reactive protein level was 9.6 mg/dl. Three months later, he remained well, and his C-reactive protein level was 1.7 mg/dl.