Table 1. Differentiating features of SS and neuroleptic malignant syndrome.

SS, serotonin syndrome

	Serotonin syndrome	Neuroleptic malignant syndrome
Inciting drug	Serotonergic agent	Dopamine antagonist
Onset	Usually < 24 h	Gradual onset (days to weeks)
Vitals	Hypertension, tachycardia, tachypnea, hyperthermia (<41℃)	Hypertension, tachycardia, tachypnea, hyperthermia (>41℃)
Core symptoms	Agitation, diarrhea, diaphoresis, tremors	Dysphagia, hypersalivation
Neuromuscular signs	Hyperreflexia, clonus, mydriasis	Bradykinesia, hyporeflexia, lead-pipe rigidity
Lab findings	Most commonly no significant lab abnormalities	Increase in creatine kinase, leukocytosis, low serum iron