Unknown poisoning — toxidrome discrimination and flumazenil

This is serotonin toxicity: rapid onset, serotonergic agents (SSRI + tramadol), hyperthermia, autonomic instability, and clonus/hyperreflexia.^[2] Sympathomimetic alone lacks sustained clonus; anticholinergic is dry; NMS is slower with lead-pipe rigidity and hyporeflexia.

Management: ABCDE + glucose; benzodiazepines titrated; external cooling; stop serotonergic agents; cyproheptadine 12 mg if enteral route safe; paralysed/intubated care if severe rigidity preventing cooling. ECG for co-ingestant Na-channel block; paracetamol level.^[1]

Flumazenil is contraindicated in unknown/mixed OD — lowers seizure threshold and can precipitate status, especially with pro-convulsant co-ingestants (e.g. TCA). Reserve for rare isolated iatrogenic BZD oversedation. Airway and directed therapy first.^[1]