Serotonin syndrome

This code represents serotonin syndrome, a potentially life-threatening drug reaction resulting from excessive serotonergic activity in the central and peripheral nervous systems. It manifests as a spectrum of mental status changes, autonomic hyperactivity, and neuromuscular abnormalities.

Use this code when documentation clearly indicates a diagnosis of serotonin syndrome, typically triggered by therapeutic drug use, intentional self-poisoning, or interactions between two or more serotonergic agents. Supporting documentation should detail the patient's symptoms consistent with the syndrome and the suspected medication(s) involved.

• Always code the specific drug(s) causing the serotonin syndrome using external cause codes (T36-T50) in conjunction with this diagnosis.
• Distinguish serotonin syndrome from neuroleptic malignant syndrome, which presents with similar but distinct features and different causative agents.
• Ensure documentation specifies whether the syndrome is acute, chronic, or resolved, if applicable, although this code does not differentiate these states.