Chapter 80: Toxicology and Antidotes

Question 1

Which resources have information on toxicology?

Answer 1

Micromedex POISONDEX & Lexicomp Lexi-Tox

Question 2

To reduce accidental poisoning in children, what can be helpful?

Answer 2

Child-resistant containers

Question 3

What is required for all rx drugs unless waived by the patient?

Answer 3

Child-resistant containers

Question 4

Which drug is excluded from child-resistant containers?

Answer 4

Nitroglycerin SL tabs

Question 5

Topical overdose management?

Answer 5

Remove contaminated clothing and wash skin with soap and water for at least 15 min

Question 6

Ocular overdose management?

Answer 6

Remove contact lenses and rinse eye/s with a gentle stream of water for at least 15 min

Question 7

Oral ingestion overdose/exposure management?

Answer 7

Remove any remaining substances from the mouth and drink a small amount of water or milk if burning!

Question 8

Which drug is no longer available but used to induce emesis for certain exposures?

Answer 8

Ipecac syrup

Question 9

The first step to the CAB’s (circulation, airway, breathing) is?

Answer 9

To evaluate if the pt has a pulse

Question 10

How is CPR given? (breath:chest compression)

Answer 10

Give 2 breaths for every 30 chest compressions

Question 11

When is activated charcoal most effective?

Answer 11

When used within 1 hour of ingestion

Question 12

How does activated charcoal work?

Answer 12

It absorbs the drug, which prevents GI absorption and systemic toxicity

Question 13

What is the dose of activated charcoal?

Answer 13

1 g/kg

Question 14

What must be done prior to using activated charcoal?

Answer 14

Airway should be protected (with intubation, if needed) to prevent aspiration

Question 15

Activated charcoal CI?

Answer 15

When the airway is unprotected (unconscious, cannot clear throat, cannot hold head upright)

Question 16

Excessive ingestion of acetaminophen can lead to ____.

Answer 16

Hepatotoxicity

Question 17

What is considered a safe dose of acetaminophen?

Answer 17

Less than 4g per day

Question 18

Hepatotoxicity is a dose-dependent adverse effect caused by the increased metabolism of APAP by CYP450 ___ to ____?

Answer 18

2E1 to NAPQI

Question 19

Phase 1 of APAP overdose?

Answer 19

1-24 hrs: commonly asymptomatic or non-specific symptoms such as nausea and vomiting

Question 20

Phase 2 of APAP overdose?

Answer 20

24-72 hrs: elevated INR, AST/ALT; symptoms from phase 1 usually subside

Question 21

Phase 3 of APAP overdose?

Answer 21

72-96 hrs: fulminant hepatic failure (e.g., jaundice, coagulopathy, renal failure, &/or death)

Question 22

Phase 4 of APAP overdose?

Answer 22

> 96 hrs: the patient recovers or receives a liver transplant

Question 23

Antidote for APAP overdose?

Answer 23

N-acetylcysteine (NAC)

Question 24

How does NAC work for APAP overdose?

Answer 24

Increases glutathione, which increases GSH. GSH converts NAPQI to mercapturic acid, which can safely be excreted from the body. If NAPQI has already bonded to hepatocytes, the damage is irreversible

Question 25

APAP levels are plotted on?

Answer 25

Rumack-Matthew nomogram to determine risk of hepatotoxicity

Question 26

What formulations does NAC come in?

Answer 26

Oral and IV

Question 27

NAC brand name?

Answer 27

Acetadote

Question 28

How is oral NAC dosed?

Answer 28

High-dose bolus x1, then lower dose for 17 doses. Repeat the dose if emesis occurs within 1 hr of administration

Question 29

How is IV NAC dosed?

Answer 29

3 infusions over a total of 21 hrs

Question 30

Anticholinergic overdose symptoms?

Answer 30

Flushing, dry skin, mydriasis with double or blurry vision | mydriasis: dilation of the pupil of the eye.

Question 31

Anticholinergic overdose treatment?

Answer 31

Primarily supportive care, rarely physostigmine

Question 32

Treatments for warfarin OD?

Answer 32

Phytonadione (Vitamin K), Prothrombin complex concentrate (Kcentra)

Question 33

Treatment for heparin & LMWH OD?

Answer 33

Protamine

Question 34

Treatments for dabigatran OD?

Answer 34

Idarucizumab (Praxbind)

Question 35

Treatments for apixaban & rivaroxaban OD?

Answer 35

Abdexanet alfa (Andexxa)

Question 36

Treatment for BZD OD?

Answer 36

Flumazenil - can cause seizures when used in pts on BZDs chronically

Question 37

Treatment for BB OD?

Answer 37

Glucagon (if unresponsive to symptomatic tx)

Question 38

Treatment for CCB OD?

Answer 38

Calcium chloride or gluconate (administer Ca IV only)

Question 39

Cyanide: smoke inhalation, nitroprusside in high doses/long durations/renal impairment treatment for OD?

Answer 39

Hydroxocobalamin (Cyanokit)

Question 40

Treatment for digoxin OD?

Answer 40

Digoxin Immune Fab (DigiFab)

Question 41

Treatment for antipsychotic OD?

Answer 41

Benztropine

Question 42

What should be administered for ethanol OD if suspected to be a chronic alcohol user?

Answer 42

Thiamine (B1) to prevent Wernicke’s encephalopathy ## Footnote Can cause increased anion gap

Question 43

In patient’s with Hydrocarbon OD (petroleum products, gasoline, kerosene, mineral oil, paint thinners), what should be avoided?

Answer 43

Do not induce vomiting; keep pt NPO d/t aspiration risk

Question 44

Treatment for insulin or other hypoglycemic OD?

Answer 44

Dextrose injection or infusion (drip), oral glucose (do not administer if pt is unconscious), Glucagon (when IV or oral dextrose cannot be administered)

Question 45

Treatment for isoniazid OD?

Answer 45

IV Pyridoxine (B6)

Question 46

Iron & aluminum OD treatment?

Answer 46

Deferoxamine (Desferal)

Question 47

Symptoms of organophosphate OD?

Answer 47

OPs block acetylcholinesterase, which increases ACh levels and causes cholinergic “SLUDD” sx: salivation, lacrimation, urination, diarrhea/defecation

Question 48

Treatment for organophosphate, including industrial insecticide, OD?

Answer 48

Atropine ## Footnote Pralidoxime: treats muscle weakness and relieves paralysis of respiratory muscles by reactivating cholinesterase

Question 49

Treatment for methotrexate OD?

Answer 49

Leucovorin (folinic acid), levoleucovorin (Fusilev), Glucarpidase (Voraxaze)

Question 50

Methylene blue is CI in pts with?

Answer 50

G6PD deficiency

Question 51

Treatment for neostigmine, pyridostigmine OD?

Answer 51

Pralidoxime

Question 52

Early sx of nicotine OD?

Answer 52

Abdominal pain, nausea

Question 53

Treatment for nicotine OD?

Answer 53

Supportive care (e.g., atropine for symptomatic bradycardia, BZDs for seizures)

Question 54

Treatment for salicylate OD?

Answer 54

Sodium bicarbonate (alkylating agent to alkalinize the urine to decrease drug absorption and increase excretion of salicylates)

Question 55

Stimulant OD treatment (including ADHD and weight loss drugs)?

Answer 55

Supportive care and BZDs for agitation or seizures

Question 56

Toxic alcohols like ethylene glycol (antifreeze), methanol treatment for OD?

Answer 56

Fomepizole ## Footnote Can cause increased anion gap

Question 57

OD of TCAs can quickly cause?

Answer 57

Fatal arrhythmias

Question 58

TCA OD treatment?

Answer 58

Sodium bicarbonate to decrease a widened QRS complex

Question 59

Valproic acid or topiramate-induced hyperammonemia treatment?

Answer 59

Levocarnitine

Question 60

What are the SLUDD symptoms for organophosphate OD?

Answer 60

Salivation, Lacrimation, Urination, Diarrhea, Defecation

Question 61

What is the combination of atropine and pralidoxime called for organophosphate OD?

Answer 61

Duodote

Question 62

Antidote for mammal bites?

Answer 62

Rabies vaccine with Human rabies immune globulin

Question 63

Black Widow spider bites and scorpion sting antidote?

Answer 63

Antivenin

Question 64

Snake bite antidote?

Answer 64

Crotalidae polyvalent immune FAB (Crofab) for copperhead and rattlesnake bites