A patient on a therapeutic dose of an SSRI develops fever 40°C, muscle rigidity, myoclonus, hyperreflexia, and diarrhea 2 hours after adding tramadol for pain. This presentation is best managed with:

• A Cyproheptadine orally — 5-HT2A/1A antagonist that directly reverses serotonin syndrome toxidrome ✓
• B Dantrolene sodium IV — specifically blocks ryanodine receptor-mediated calcium release in malignant hyperthermia
• C Bromocriptine — dopamine agonist reversing neuroleptic malignant syndrome features
• D Amantadine IV — NMDA antagonist reducing glutamate-mediated excitotoxicity in serotonin syndrome

Explanation

This is serotonin syndrome caused by SSRI (serotonin reuptake inhibition) combined with tramadol (weak serotonin reuptake inhibitor + mu-opioid agonist). The clinical triad — altered mental status, autonomic instability, and neuromuscular abnormalities (myoclonus, hyperreflexia, clonus) — distinguishes it from NMS (bradykinesia, lead-pipe rigidity, high CPK, no myoclonus). Cyproheptadine, a 5-HT2A antagonist, is the specific antidote; benzodiazepines control agitation and hyperthermia. Dantrolene is for malignant hyperthermia and can be used adjunctively in severe cases but is not the specific agent. Bromocriptine is for NMS.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

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Written and medically reviewed by the StethoPrep medical team.