I had a crazy case of Tricyclic Overdose while on an overnight shift at Janus General.
Initial and Post-Treatment EKGs
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
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 (11482860)
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. (23636658)
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.(20507243)
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…
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