A patient on psychotropic medication presents with hyperthermia, autonomic instability, and neuromuscular excitability. What is the likely diagnosis?

A patient on psychotropic medication presents with hyperthermia, autonomic instability, and neuromuscular excitability. What is the likely diagnosis?

• A. Anticholinergic toxicity
• B. Malignant hyperthermia
• C. Neuroleptic malignant syndrome
• D. Serotonin syndrome

Answer: (D)

Excess serotonergic activity from psychotropic medications leads to serotonin syndrome, which presents with rapid-onset hyperthermia, autonomic instability (tachycardia, hypertension, diaphoresis), and neuromuscular excitability such as tremor, clonus, and hyperreflexia. The pattern of neuromuscular findings, especially clonus and hyperreflexia, along with the possible agitation, GI symptoms, and rapid course after starting or combining serotonergic drugs, points to this syndrome. Anticholinergic toxicity would more likely show dry skin and mucous membranes with decreased sweating. Malignant hyperthermia occurs in the setting of anesthesia with rigidity and metabolic derangements. Neuroleptic malignant syndrome is tied to dopamine antagonists and develops more gradually with "lead-pipe" rigidity and elevated CK. The combination of hyperthermia, autonomic changes, and neuromuscular excitability in a patient on serotonergic meds best fits serotonin syndrome.

Excess serotonergic activity from psychotropic medications leads to serotonin syndrome, which presents with rapid-onset hyperthermia, autonomic instability (tachycardia, hypertension, diaphoresis), and neuromuscular excitability such as tremor, clonus, and hyperreflexia. The pattern of neuromuscular findings, especially clonus and hyperreflexia, along with the possible agitation, GI symptoms, and rapid course after starting or combining serotonergic drugs, points to this syndrome.

Anticholinergic toxicity would more likely show dry skin and mucous membranes with decreased sweating. Malignant hyperthermia occurs in the setting of anesthesia with rigidity and metabolic derangements. Neuroleptic malignant syndrome is tied to dopamine antagonists and develops more gradually with "lead-pipe" rigidity and elevated CK. The combination of hyperthermia, autonomic changes, and neuromuscular excitability in a patient on serotonergic meds best fits serotonin syndrome.