81. Toxicology Flashcards
eWhat are some common C-R packaging?
Screw caps
Unit-dose packaging
Card adherence
Safety packaging
Initial overdose management for topical exposure
Removed contaminated clothing and wash skin with soap and water for 10 min to remove poison from skin
Initial overdose management for ocular exposure
Remove contact lenses and rinse eye(s) with gentle stream of water for at least 15 min
When should 911 be called for overdose?
It pt is unconscious, having difficulty breathing, appears agitated or having seizure
If pulseless, do CPR
Activated charcoal is most effective when used within ___
1 hr of ingestion
How does activated charcoal work?
Adsorbs drug, which prevents GI absorption and systemic tox
What is typical dosing for activated charcoal?
1g/kg
Prior to using activated charcoal, the air way should be. ___
protected (with intubation if needed) to prevent aspiration
When is activated charcoal contraindicated?
When airway is unprotected - unconscious, cannot clear throat, cannot hold head upright
Intestional obstruction
GI tract not intact or when there is decreased peristalsis
Hydrocarbons such as ____ can increase risk of aspirations
petroleum products including gasoline and paint thinner
Hepatotoxicity is dose-dependent adverse effect caused by increased metabolism of acetaminophen by CYP___ to ____
CYP2E1
NAPQI
How does NAPQI cause liver injury/failure
Covalently binds to liver cell proteins and cause liver injury»_space; liver failure
Describe Phase 1 of APAP tox
1-24 hrs
commonly asymptomatic or non-specific symptoms, such as N/V
Describe Phase 2 of APAP tox
24-48hrs
Labs elevated INR, AST/ALT
Any symptoms from phase 1 usually subside
Describe Phase 3 of APAP tox
48-96hrs
Fulminant hepatic failure (e.g. jaundice, coagulopathy, renal failure, and/or death)
Describe Phase 4 of APAP tox
> 96 hrs
Pt recovers or receives a liver transplant
How does NAC work for APAP tox?
NAC (Acetadote) is free radical scavenger and precursor to glutathione (GSH), ultimately increasing GSH»_space; GSH converts NAPQI to mercapturic acid»_space; safely excreted
NAC formulations
PO and IV
Typical dosing for oral NAC vs IV NAC
Oral: high dose given once, then lower dose for 17 doses, repeat if emesis occurs within 1 hr of admin
IV: 3 infusions over total of 21 hrs
Symptoms of anticholinergic overdose (atropine, diphenhydramine, dimenhydrinate, scopolamine, Atropa belladonna (Deadly nightshade), jimson weed)
Flushing - red as a beet
Dry skin and mucous membranes - dry as a bone
Mydriasis with double/blurry vision - blind as a bat
Altered mental status - mad as a hatter
Fever - hot as a hare
Andexanet alfa (Andexxa) can reverse which anticoags?
Apixaban, rivaroxaban
Treatment for anticholinergic overdose
Primarily supportive care
Rarely physostigmine is given - inhibits enzyme that breaks down ACh, acetylcholinesterase, which increase ACh and decrease anticholinergic toxicity
Idarucizumab (Praxbind) can reverse which anticoags?
Dabigatran
Phytonadione (Vit K) can reverse which anticoags?
Warfafrin
Protamine can reverse which anticoags?
Heparin, LMWH
Prothrombin complex concentrate (Kcentra) can reverse which anticoags?
warfarin, factor Xa inhibitors
Treatment for antipsychotic overdose
Primarily supportive care
Bezntropine can be given for dystonias and bicarbonate can be given if QRS-interval widening
Treatment for BZD overdose
Flumazenil - can cause seizures when used in pts on BZD chronically
Sometimes used off label for non-BZD hypnotic overdose (e.g. zolpidem) but not routinely recommended
Treatment for beta-blocker overdose
Glucagon (if unresponsive to symptomatic treatment)
High dose insulin with glucose may be used in pts refractory to glucagon
Lipid emulsion to enhance elimination of some lipophilic drugs
Treatment for CCB overdose
Same as beta-blockers:
Glucagon (if unresponsive to symptomatic treatment)
High dose insulin with glucose may be used in pts refractory to glucagon
Lipid emulsion to enhance elimination of some lipophilic drugs
PLUS calcium (chloride or gluconate): IV only, avoid fast infusion, monitor ECG, do not infuse calcium in same line as phosphate-containing solutions
Treatment for cyanide (smoke inhalation, nitroprusside in high doses/long durations/renal impairment) overdose
hydroxocobalamin (Cyanokit)
Sodium thiosulfate + sodium nitrite (Nithiodote)
Treatment for digoxin, oleander, foxglove overdose
Digoxin immune fab (DigiFab)
Each DigiFab 40mg vials binds ~0.5mg digoxin; when amt ingested or digoxin level is unknown, max adult dose is 20 vials
Interferes with digoxin levels drawn after it has been given
Treatment for ethanol (alcoholic drinks) toxicity
If suspected chronic alcohol user, administer thiamine (vit B1) to prevent Wernicke’s encephalopathy (neurological damage)
Can cause increase anion gap
Treatment for heavy metal (arsenic, copper, gold, lead, mercury, thallium) toxicity
Dimercaprol: aresenic, gold, mercury
Dimercaprol + CaNa2 EDTA OR Succimer (Chemet) + DMSA: Lead
Penicillamine: copper
Ferric hexacyanoferrate (“Prussian blue” (Radiogardase)): Thallium
Treatment for hydrocarbon (petroleum products) toxicity
Do not induce vomiting
Keep pt NPO d/t aspiration risk
Treatment for insulin or other hypoglycemic toxicity
Dextrose injection or infusion (drip), oral glucose (do not administer if unconscious)
Glucagon (when IV or PO dextrose cannot be administered)
SU-induced hypoglycemia: octreotide (Sandostatin)
Teratment for isoniazid toxicity
Pyridoxine (Vit B6), BZD and/or barbituates
For acute neurotox (seizure, coma), administer IV pyridoxine
PO pyridoxine 10-50mg used daily with isoniazid to prevent neuropathies
Treatment for iron and aluminum toxicity
Deferoxamine (Desferal): iron and aluminum
Treatment for organophosphates (OPs) including industrial insecticides) toxicity
OPs block ACE which increase ACh levels and causes cholinergic “SLUDD” symptoms salivation, lacrimation, urination, diarrhea/defecation
Atropine - anticholinergic which blocks effect of ACh to reduce SLUDD symptoms
Pralidoxime (Protopam) - treats muscle weakness and relieves paralysis or respiratory muscles by reactivating cholinesterase that was inactivated by exposure to OPs
Atropine and pralidoxime combo can be used (DuoDote)
Treatment for methotrexate toxicity
Leucovorin (folinic acid), levoleucovorin (Fusilev), glucarpidase (Voraxaze) - rescue after high dose in cancer treatment, after accidental overdose or to reduce tox wand counteract effects of impaired elimination
Treatment for methemoglobinemia from topical benzocaine (in OraGel or teething products), dapsone, nitrates, or sulfonamides
Methylene blue (ProvayBlue)
Note: contraindicated in pts with G6PD deficiency; avoid admin with SSRIs and SNRIs
Treatment for neostigmine, pyridostigmine toxicity
Pralidoxime (Protopam) - counteracts muscle weakness and/or respiratory depression secondary to overdose of ACE meds used to treat myasthenia gravis
Atropine or glycopyrrolate can be given to prevent bradycardia from neostigmine
Early symptoms of nicotine (including e-cig) toxicity
Abd pain, nausea, diaphoresis, tachycardia, tremors
Later symptoms of nicotine (including e-cig) toxicity
Bradycardia, dyspnea, lethargy, coma, seizures
Treatment for nicotine (including e-cig) toxicity
Supportive care (e.g. atropine for symptomatic bradycardia, BZDs used for seizures)
what can be used to reveres paralytics (e.g. rocuronium, vecuronium, pancuronium)
Neostigmine methylsulfate (Bloxiverz): rocuronium, vecuronium, pancuronium
Sugammadex (Bridion): rocuronium, vecuronium
Treatment of salicylate toxicity
Salicylates are acidic.
Sodium bicarbonate is alkalinizing agent, can alkalinize urine»_space; decrease drug reabsorption and increase excretion of salicylates and other weak acids
Treatment of stimulant overdose (amphetamines including ADHD and weight loss drugs, cocaine, ephedrine, caffeine, theophylline, MDMA (ecstasy))
Supportive care for agitation or seizures (BZD)
Treatment of toxic alcohols (ethylene glycol (antifreeze), diethylene glycol, ethanol) toxicity
Can cause increase anion gap
Fomepizole is preferred; ethanol (2nd line)
Treatment of TCA overdose
Overdose can quickly cause fatal arrhythmias
Sodium bicarbonate - to decrease widened QRS complex
Supportive care for agitation/seizures (BZD) if present
Vasopressors may be needed for hypotension
Treatment for valproic acid or topiramite-induced hypoammonemia
Levocarnitine (Carnitor)
If opioids and acetaminophen were both ingested, ___ should be given first
naloxone
What can be signs of opioid overdose?
Somnolence, shallow labored breathing, pinpoint pupils
Naloxone should be administered
What can be used to determine if NAC should be given in APAP toxicity?
Rumack-Matthew nomogram
Tachycardia, seizures or severe agitation can be from multiple causes. Give ___
BZD
QT prolongation can be caused by ___. Check ECG and give ___ if QRS is widened.
TCAs
sodium bicarbonate
Antidote for animal bites
Rabies vaccine (RabAvert, Imovax Rabies)
+ human rabies immune globulin (HyperRAB S/D, Imogam Rabies HT)
Antidote for black widow spider bites
Antivenin for Latrodectus mactans
Antidote for scorpion stings
Antivenin immune FAB Centruroides (Anascorp)
Antidote for snake bites (eastern coral snake, Texas coral snake, copperhead, rattlesnake)
Crotalidae polyvalent immune FAB (CroFab) for copperhead and rattlesnake bites
Crotalidae Immune F(ab’)2 (Anavip) for rattlesnake bites)
