A patient on an SSRI for depression develops fever, muscle rigidity, diaphoresis, and hyperreflexia 2 days after adding tramadol for back pain. This represents:
- A Serotonin syndrome from excess serotonergic activity ✓
- B Neuroleptic malignant syndrome from dopamine depletion
- C Malignant hyperthermia triggered by tramadol
- D Anticholinergic toxidrome from SSRI-tramadol combination
Explanation
Tramadol has dual action: opioid agonism and inhibition of serotonin and norepinephrine reuptake. When combined with an SSRI (which also blocks serotonin reuptake), serotonin levels in the synapse accumulate excessively. Serotonin syndrome manifests as the classic triad of altered mental status, autonomic instability (hyperthermia, diaphoresis, tachycardia), and neuromuscular abnormalities (clonus, hyperreflexia, myoclonus). It differs from NMS by the presence of clonus/hyperreflexia and rapid onset (hours). Treatment involves stopping the offending agents and cyproheptadine (5-HT2A antagonist) in severe cases.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
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Written and medically reviewed by the StethoPrep medical team.