Pathophysiology
Clinical meaning
Serotonin syndrome results from excess serotonergic activity in the central nervous system, typically caused by drug interactions or overdose of medications that increase serotonin levels. Excessive activation of 5-HT1A and 5-HT2A receptors in the brainstem and spinal cord produces a characteristic triad: altered mental status, autonomic instability, and neuromuscular excitability. The condition does not occur naturally—it is always drug-induced. Onset is rapid, typically within 2-72 hours of a causative medication change. The nurse monitors for the characteristic signs, maintains patient safety, and reports findings immediately.