Antidepressants Toxicity

YouTube LinkDr. Sean Nordt delivers a comprehensive pharmacology lecture on antidepressants, their mechanisms, and the management of toxicity cases in emergency settings. The board-certified emergency physician, pharmacologist, and toxicologist walks through the complex pharmacology of psychiatric medications, focusing on their potentially deadly complications and how to recognize and treat them.• Cyclic antidepressants cause toxicity through fast sodium channel blockade, leading to QRS widening and ventricular dysrhythmias• Sodium bicarbonate is the cornerstone treatment for cyclic antidepressant toxicity, working by increasing pH and altering cardiac binding• SSRIs and SNRIs have distinct adverse effect profiles, with SNRIs posing greater risk in overdose scenarios• Bupropion overdose commonly causes seizures and QRS widening through cardiac gap junction blockade• MAOIs can cause hypertensive crisis and severe serotonin syndrome, especially with tyramine-rich foods or drug interactions• Serotonin syndrome is characterized by hyperreflexia and clonus, distinguishing it from neuroleptic malignant syndrome• Treatment approaches differ for serotonin toxicity (benzodiazepines, cooling), NMS (supportive care), and malignant hyperthermia (dantrolene)• Antiemetics like metoclopramide and promethazine can cause extrapyramidal effects treatable with anticholinergics