“Podcast 98 – Cyclic (Tricyclic) Antidepressant Overdose” From EMCrit

Here is the link to the show notes and podcast of Podcast 98 – Cyclic (Tricyclic) Antidepressant Overdose; May 14, 2013 by Dr. Scott Weingart.

[Note to myself: Whenever I review this post, I also need to review  “CritCases 1: Massive TCA (Tricyclic Antidepressant Overdose)” – Help From Emergency Medicine Cases
Posted on March 17, 2019 by Tom Wade MD.]

I have included the show notes of Podcast 98 in this post. The posts in this blog are my study notes [peripheral brain] and going  through show notes this way helps to fix them in my mind.

Podcast 98 – Cyclic (Tricyclic) Antidepressant Overdose by  37 Comments

 

I had a crazy case of Tricyclic Overdose while on an overnight shift at Janus General.

Initial and Post-Treatment EKGs

Initial

Post Treatment

 

List of Tricyclic Agents from Wikipedia.org

  • Amitriptyline (Tryptomer, Elavil)
  • Amitriptylinoxide (Amioxid, Ambivalon, Equilibrin)
  • Butriptyline (Evadyne)
  • Clomipramine (Anafranil)
  • Demexiptiline (Deparon, Tinoran)
  • Desipramine (Norpramin, Pertofrane)
  • Dibenzepin (Noveril, Victoril)
  • Dimetacrine (Istonil, Istonyl, Miroistonil)
  • Dosulepin/Dothiepin (Prothiaden)
  • Doxepin (Adapin, Sinequan)
  • Imipramine (Tofranil, Janimine, Praminil)
  • Imipraminoxide (Imiprex, Elepsin)
  • Lofepramine (Lomont, Gamanil)
  • Melitracen (Deanxit, Dixeran, Melixeran, Trausabun)
  • Metapramine (Timaxel)
  • Nitroxazepine (Sintamil)
  • Nortriptyline (Pamelor, Aventyl, Norpress)
  • Noxiptiline (Agedal, Elronon, Nogedal)
  • Pipofezine (Azafen/Azaphen)
  • Propizepine (Depressin, Vagran)
  • Protriptyline (Vivactil)
  • Quinupramine (Kevopril, Kinupril, Adeprim, Quinuprine)

Additionally…

  • Amineptine (Survector, Maneon, Directim) Norepinephrine-dopamine reuptake inhibitor
  • Iprindole (Prondol, Galatur, Tetran) 5-HT2 receptor antagonist
  • Opipramol (Insidon, Pramolan, Ensidon, Oprimol) ? receptor agonist
  • Tianeptine (Stablon, Coaxil, Tatinol) Selective serotonin reuptake enhancer
  • Trimipramine (Surmontil) 5-HT2 receptor antagonist and moderate-potency norepinephrine reuptake inhibitor.

And of course, the non-TCA agents…

  • Diphenhydramine [This is a link to a case report of diphenhydramine sodium channel toxicity
  • Cocaine
  • Cyclobenzaprine (I add this one to the list, b/c there can be TCA-like effects in toxicity, but it seems the potential for cardiac effects is markedly less though still possible. (J Emerg Med 1995;13(6):781-5) This one is from Bryan Hayes)

Pharmacologic Effects of TCAs

K+ Channel Blockade QTC Prolongation
NE & Serotonin Reuptake Inhibition Initial hypertension quickly followed by hypotension
Na+ Channel Blockade QRS Prolongation
Hypotension — depresses myocardial contractility
Ventricular dysrhythmias
Brugada-like findings on EKG
Muscarinic Anticholinergic Receptor Antagonism Anticholinergic Toxidrome
Antihistaminergic CNS stimulation or sedation
Alpha1 Adrenergic Antagonism Hypotension
GABA-A Receptor Blockade Seizures

This chart was taken from the excellent Resus Review Blog by Charles Bruen

Sodium Bicarbonate

Increases amount of drug in non-ionized form and may decrease binding to Na-channels [cite]11482860[/cite]

May need many, many amps. For some reason the sodium and the bicarb don’t rise significantly in severe toxicity

My goals are QRS duration <100, hemodynamically stable, Na ~150, pH ~7.5

Electrolyte Abnormalities

Beware of hypokalemia and hypocalcemia

Send VBG with lytes at least Q1 hour

Hyperventilation

To promote alkalosis

Hypertonic Saline

If the patient is too alkalotic or out of amps of Bicarb

Sodium Acetate

Can substitute for NaBicarb. This article gives dosing recommendations and precautions.*

* Sodium acetate as a replacement for sodium bicarbonate in medical toxicology: a review [PubMed Abstract] [PMC Full Text] [Full Text PDF].

Magnesium

May help, though risk of Torsades is low as long as the patient remains tachycardic

Lidocaine

Even though lidocaine is another Na-Channel Blocker, it actually antagonizes the effects of the TCA-like mediciations. As a Vaughan Williams Class IB agent, For additional information, this review discusses the pertinent issues.[cite]http://www.ncbi.nlm.nih.gov/pubmed/20507243[/cite]

VasoPressors

Norepi or Epi

Intralipids

Certainly for cardiac arrest and probably for hypotension/increasing pressor necessity

For this or any other Lipid Question, you need to go immediately to the Lipid Rescue Site

You can find the Lipid Administration Instruction Sheet there, which should be hanging somewhere on the wall of your ED.

ECMO

The last resort for tox instability

Want More?

My friends Sean Nordt and Stu Swadron did a great EM:RAP episode on this 2 months ago

Here is a review and guideline article.

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