Wednesday, April 14, 2021

Tricyclic AD Overdose

Canadi EM - By Sophie Ramsden - April 13, 2021
Management Priorities
1) Manage ABCs – Treat hypotension with IV fluids and vasopressors if needed. Norepinephrine or epinephrine are first-line choices. There is limited experimental evidence in animals suggesting that epinephrine may be more effective at reducing the cardiotoxic effects of TCAs. Norepinephrine is a physiologically sensible choice, given the alpha blocking effects of TCAs, as well as their inhibition of norepinephrine reuptake.​
Intubation should be considered early, especially in a known massive overdose. Consider intubating earlier for GCS<8, refractory seizures, hypoventilation, or airway compromise​3.
2) Gastric decontamination – If less than 1 hour from ingestion (or unknown time), give activated charcoal. This requires the patient to be protecting their airway, or intubated, as there is a significant risk of aspiration with activated charcoal (a risk not completely eliminated by intubation). Particularly in a massive overdose, consider giving activated charcoal even up to 4 hours post ingestion. The anticholinergic effects of the drug slow gastric emptying, so there may still be some benefit from late gastric decontamination. Consider gastric lavage for a massive overdose within 1 hour of ingestion, again necessitating a protected airway.​3​
3) Sodium bicarbonate – Start with 1-2 mEq/kg boluses of a 1 mEq/mL solution (50-100 mEq, or 1-2 amps), repeating every few minutes until the QRS narrows. Then start an infusion of 150 mEq bicarb in 1L D5W with 40 mEq KCL at ~250 mL/hr (titrated to QRS and pH targets). Goals of therapy are QRS < 100 ms and pH 7.5-7.55.”