Differential diagnosis of serotonin syndrome
| Serotonin syndrome | Neuroleptic malignant syndrome | Anticholinergic toxicity | |
|---|---|---|---|
| Causative agent | Serotonergic agent | Dopamine antagonist Withdrawal from dopamine agonist | Anticholinergic agent |
| Onset | Within 24 hours | Within days to weeks | Within 1–2 hours |
| Resolution | Within 24 hours | In approximately 9 days | Within hours to days |
| Features similar to those of serotonin syndrome | — | Hyperthermia Altered mental state Diaphoresis Autonomic instability | Mydriasis Hyperthermia Agitation, delirium Visual hallucinations |
| Distinct features | Myoclonus Hyperreflexia Mydriasis Tremor Diarrhea Nausea, vomiting | Bradyreflexia Lead pipe rigidity Extrapyramidal features Absence of neuromuscular excitation | Dry skin and mucous membranes Urinary retention Decreased bowel sounds Normal muscle tone and reflexes |