Antidepressant poisoning
Risk by class (tricyclics, venlafaxine, bupropion, citalopram, MAOIs, SSRIs and mirtazapine), the QRS and aVR rules for sodium channel blockade, bicarbonate and airway management, QT monitoring, seizures and serotonin toxicity.
Tier 1Condition
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Antidepressants are among the drugs most often taken in deliberate self-poisoning in Australia. Risk depends almost entirely on the class.
- Tricyclics (amitriptyline, nortriptyline, dosulepin, clomipramine, doxepin) cause most deaths. They kill through sodium channel blockade, seen as QRS widening.
- Venlafaxine, bupropion and citalopram sit in the middle: seizures, serotonin toxicity or QT prolongation.
Loading the rest of the note…
Finished reading?
Sources
- Therapeutic Guidelines: Toxicology and Toxinology (December 2024 update, including new tramadol and tapentadol monographs separated from SNRI poisoning)AU/NZTherapeutic Guidelines Limited, 2024
- Poisons Information Centre (13 11 26)AU/NZNSW Poisons Information Centre, Sydney Children's Hospitals Network
- Boehnert MT, Lovejoy FH. Value of the QRS duration versus the serum drug level in predicting seizures and ventricular arrhythmias after an acute overdose of tricyclic antidepressants. N Engl J Med 1985;313:474-9New England Journal of Medicine, 1985
- Liebelt EL, Francis PD, Woolf AD. ECG lead aVR versus QRS interval in predicting seizures and arrhythmias in acute tricyclic antidepressant toxicity. Ann Emerg Med 1995;26:195-201Annals of Emergency Medicine, 1995
- Whyte IM, Dawson AH, Buckley NA. Relative toxicity of venlafaxine and selective serotonin reuptake inhibitors in overdose compared to tricyclic antidepressants. QJM 2003;96:369-74AU/NZQJM, 2003
- Isbister GK, Polanski R, Cooper JM et al. Duloxetine overdose causes sympathomimetic and serotonin toxicity without major complications. Clin Toxicol 2022;60:1019-23AU/NZClinical Toxicology, 2022
- Hoegberg LCG, Gosselin S, Buckley NA et al. Recommendations from the Clinical Toxicology Recommendations Collaborative on the administration of activated charcoal in acute oral overdose. Clin Toxicol 2026;64:419-75Clinical Toxicology, 2026
- Yates C et al. Extracorporeal treatment for tricyclic antidepressant poisoning: recommendations from the EXTRIP workgroup. Semin Dial 2014;27:381-9Seminars in Dialysis, 2014
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Personal emails, About story and Australian-style copy