Which of the following is NOT a category of serotonin syndrome symptoms?

Which of the following is NOT a category of serotonin syndrome symptoms?

• A. Autonomic instability
• B. Hyponatremia
• C. Neuromuscular abnormalities
• D. Mental status changes

Answer: (B)

Recognizing the triad of serotonin syndrome symptoms helps here. Serotonin syndrome classically presents with autonomic instability (like tachycardia, hypertension, fever, sweating), neuromuscular abnormalities (clonus, hyperreflexia, tremor), and mental status changes (agitation, confusion). Hyponatremia, while it can occur with some antidepressants in certain contexts, is not part of the characteristic symptom categories of serotonin syndrome. So hyponatremia is not a defining feature of the syndrome, making it the correct answer. The remaining categories—autonomic instability, neuromuscular abnormalities, and mental status changes—fit the classic presentation.

Recognizing the triad of serotonin syndrome symptoms helps here. Serotonin syndrome classically presents with autonomic instability (like tachycardia, hypertension, fever, sweating), neuromuscular abnormalities (clonus, hyperreflexia, tremor), and mental status changes (agitation, confusion). Hyponatremia, while it can occur with some antidepressants in certain contexts, is not part of the characteristic symptom categories of serotonin syndrome. So hyponatremia is not a defining feature of the syndrome, making it the correct answer. The remaining categories—autonomic instability, neuromuscular abnormalities, and mental status changes—fit the classic presentation.