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
• 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 TCAsK+ Channel BlockadeQTC ProlongationNE & Serotonin Reuptake InhibitionInitial hypertension quickly followed by hypotensionNa+ Channel BlockadeQRS Prolongation
Hypotension — depresses myocardial contractility
Ventricular dysrhythmias
Brugada-like findings on EKGMuscarinic Anticholinergic Receptor AntagonismAnticholinergic ToxidromeAntihistaminergicCNS stimulation or sedationAlpha1 Adrenergic AntagonismHypotensionGABA-A Receptor BlockadeSeizures

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 [1]

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. [2]Intubation & Sedation

Be very careful the patient doesn’t become hypercapneic

Sedate with benzo or propofol to raise seizure threshold

Gastric Decon and/or Lavage

If time of ingestion <1 hour ago and airway is protected

We use a commercial device: the Easi-Lav system

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.[3]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.

Shout-Outs

Medcalc sent me some freebie codes for their new IOS version of the app. Join the mailing list to be in the running (see the area below to sign up for the mailing list)

Daren Lewis of leadingvisually.com designed the wonderful Janus General logo; consider him if you need any message design.

Now on to the podcast…References

1. K. Blackman, S.G. Brown, and G.J. Wilkes, "Plasma alkalinization for tricyclic antidepressant toxicity: a systematic review.", Emergency medicine (Fremantle, W.A.), 2001. http://www.ncbi.nlm.nih.gov/pubmed/11482860
2. M.J. Neavyn, E.W. Boyer, S.B. Bird, and K.M. Babu, "Sodium Acetate as a Replacement for Sodium Bicarbonate in Medical Toxicology: a Review.", Journal of medical toxicology : official journal of the American College of Medical Toxicology, 2013. http://www.ncbi.nlm.nih.gov/pubmed/23636658
3. A. Foianini, T. Joseph Wiegand, and N. Benowitz, "What is the role of lidocaine or phenytoin in tricyclic antidepressant-induced cardiotoxicity?", Clinical toxicology (Philadelphia, Pa.), 2010. http://www.ncbi.nlm.nih.gov/pubmed/20507243

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