Source / episode info

• **Episode:**451
• **Title:**Divine Intervention Episode 451: Serotonin Syndrome (with integrations)
• **Published:**2023-04-12
• Source:Episode page

One-liner

Episode 451 details the pathophysiology, clinical presentation (hyperreflexia, clonus), precipitating agents (SSRIs, SNRIs, MAOIs, TCAs, Linezolid), and management of Serotonin Syndrome, while also reviewing IV drug-related endocarditis and classic drug interactions.

High-yield summary

• Pathophysiology: SS results from excessive serotonergic neurotransmission due to multiple drugs that inhibit serotonin reuptake (e.g., SSRIs, SNRIs) or block its breakdown (e.g., MAOIs).
• Clinical Triad: The classic signs include hyperreflexia, clonus (especially inducible), and myoclonus. Hyperthermia is common but not always present.
• Management Priority: Immediate withdrawal of all offending agents, followed by supportive care, IV benzodiazepines (e.g., lorazepam) for hyperadrenergic symptoms, and then cyproheptadine (a 5-HT receptor antagonist).
• Endocarditis Pearl: In intravenous drug users, right-sided endocarditis (tricuspid valve) is common; blood cultures must be obtained before starting empiric antibiotics.
• Drug Interaction Trap: Be aware of non-classic serotonergic agents like Tramadol, Dextromethorphan, St. John's Wort, and Methylene Blue, which can precipitate SS when combined with other serotonergic drugs.

Learning objectives

• Identify the pathophysiology and precipitating agents of Serotonin Syndrome.
• Differentiate the clinical presentation of Serotonin Syndrome from other hyperthermic/neuromuscular syndromes (e.g., NMS, MHS, Anticholinergic Toxicity).
• Outline the stepwise management protocol for acute Serotonin Syndrome.
• Recognize common drug interactions that increase serotonergic activity (MAOIs, SSRIs, TCAs, etc.).
• Understand the typical site of endocarditis in intravenous drug users and appropriate diagnostic workup.

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