toxicology/antidotes

When is activated charcoal most effective?

Used within 1 hour of ingestion

Activated charcoal dose

1g/kg

Which compounds increase the risk of aspiration if used with activated charcoal?

Hydrocarbons (petrolatum, gasoline, paint thinner)

When is activated charcoal contraindicated?

Airway is unprotected, intestinal obstruction, GI tract not intact

Examples of an unprotected airway

Patient is unconscious, can’t clear their throat or hold head upright

What occurs in the first phase (1-24 hours) of acetaminophen overdose?

Asymptomatic or nausea/vomiting

What occurs in the second phase (24-72 hours) of acetaminophen overdose?

Increased INR, ALT, AST (evidence of hepatotoxicity)

What occurs in the third phase (72-96 hours) of acetaminophen overdose?

Fulminant hepatic failure (jaundice, coagulopathy, renal failure, death)

What occurs in the fourth phase (> 96 hours) of acetaminophen overdose?

Patient recovers or needs a liver transplant

Acetaminophen overdose antidote

N-acetylcysteine (Cetylev, Acetadote IV)

Opioid overdose antidote

Naloxone (Narcan, Nasal) or Nalmefene (Revex, IV)

Anticholinergic overdose antidote

Physostigmine (severe cases only)

Organophosphate overdose antidote

Atropine, Pralidoxime (Protopam) or both Atropine and Pralidoxime (DuoDote, ATNAA)

Digoxin overdose antidote

DigiFab

Beta blocker overdose antidote

Glucagon

Calcium channel blocker overdose antidote

IV calcium (can also use glucagon)

Warfarin overdose antidote (not actively bleeding)

Phytonadione (Vitamin K)

Warfarin overdose antidote (actively bleeding)

Kcentra (Prothrombin complex concentrates)

LMWH antidote

Protamine

Heparin antidote

Protamine

Apixaban, Rivaroxaban antidote

Andexanet alfa (Andexxa)

Dabigitran antidote

Idarucizumab (Praxbind)

Benzodiazepine antidote

Flumazenil (Romazicon)

What can happen if you give flumazenil in a patient who takes benzodiazepines chronically?

It can cause seizures

Antidote for cyanide from smoke inhalation, high doses of nitroprusside (or long duration/renal impairment)

Hydroxocobalamin (Cyanokit)

Ethanol “antidote”

Thiamine (Vitamin B1) to prevent Wernicke’s encephalopathy

Alternative antidote for cyanide

Sodium thiosulfate and sodium nitrite (Nithiodote)

Arsenic antidote

Dimercaprol

Gold antidote

Dimercaprol

Mercury antidote

Dimercaprol

Thalium antidote

Ferric hexacyanoferrate [“Prussian blue” (Radiogardase)]

Copper antidote

Penicillamine

Antidote for too much insulin or hypoglycemia

Dextrose, Oral Glucose, Glucagon

Sulfonylurea-induced hypoglycemia antidote

Octreotide (Sandostatin)

Isoniazid antidote

Pyridoxine (Vitamin B6)

Iron antidote

Deferoxamine (Desferal)

Aluminum antidote

Deferoxamine (Desferal)

Antidote for iron overload from blood transfusions

Deferiprone (Ferriprox) or Deferasirox (Exjade, Jadenu)

Methotrexate antidote

Leucovorin, Levoleucovorin or IV sodium bicarb, Glucarpidase

Methemoglobinemia antidote

Methylene blue (ProvayBlue, contraindicated in G6PD deficiency)

What can cause methemoglobinemia?

topical benzocaine, dapsone, nitrates, or sulfonamides

Rocuronium, Vecuronium and Pancuronium antidote

Neostigmine (Bioxiverz)

Rocuronium, Vecuronium antidote

Sugammadex (Bridion)

Salicylates antidote

Sodium bicarbonate

Stimulants antidotes

Supportive care and benzodiazepines

Antidotes for toxic alcohols such as ethylene glycol (antifreeze) or diethylene glycol, methanol)

Fomepizole

Antidote for mushrooms

Treat bradycardic symptoms with atropine

Nicotine antidiotes

Atropine for bradycardia, benzodiazepines for seizures

Antidote for TCAs

Sodium bicarbonate to treat widened QRS complex

Valproic acid or topiramate induce hyperammonemia antidote

Levocarnitine (Carnitor)

Antidotes for mammal bites

Rabies vaccine + human rabies immune globulin

Human rabies immune globulin brand names

HyperRAB S/D, Imogam Rabies-HT

Black Widow Spider Bites antidote

Antivenin for Latrodectus mactans

Scorpion stings antidote

Antivenin immune FAB Centruroides (Anascorp)

Snake bite antidotes

CroFab (Crotalidae polyvalent immune Fab), Anavip

What can alcohol poisoning increase in the body?

increases anion gap

Early symptoms of nicotine poisoning

Abdominal pain, nausea, tremors, tachycardia, diaphoresis

Late symptoms of nicotine poisoning

Bradycardia, dyspnea, lethargy, coma, seizures

Atropine MOA

Blocks Ach at the muscarinic Ach receptor

Anticholinergic side effects

Flushing, dry skin, mydriasis, blurry vision, delirium, fever

Organophosphate poisoning symptoms

SLUDD

SLUDD

Salivation, Lacrimation, Urination, Diarrhea, Defecation