Toxicology Flashcards
2 drugs used for gastric decontamination + how they work
activated charcoal = toxin abs ans excreted in feces **only good w/in 1 hr
Ipecac = emetic **only good w/in 30 mins
main problem with charcol
vomit charcoal –> aspirate –> death
main problems with Ipecac
- abused w/ eating disorders
2. electrolyte imbalance; cardiotoxicity
type of toxin that can be removed with hemodialysis
water soluble toxins that are NOT highly protein bound
How do you remove toxins that are highly protein bound?
hemoperfusion (blood pass thru charcol filter)
Examples of drugs that are removed by hemoperfusion
Phenytoin, Barbs, Carbamazapine, Theophylline
β Blocker w/out ɑ Blocker is CI in the treatment of sympathomimetic OD bc…
unopposed ɑ receptor action –> HTN crisis
describe the phases of acetaminophen toxicity
Phase 1 (30 min-4 hrs) ~ normal or anorexia, pallor, diaphoresis, N/V
Phase 2 (24-48 hrs) ~ ↓severity of symptoms, but RUQ pain + ↓renal function **RUQ Pain: liver damage --> abnormal enzymes / function --> ↑PT time
Phase 3 (3-5 days) ~ coagulation defects, jaundice, hepatic encephalopathy, renal failure
Phase 4 (4days to 2 weeks): resolution or death
do NOT stop NAC once started; complete 1 Loading Dose + (#) Maintenance Doses
17
What is acetaminophen “risk line”
(~150 ug/mL @ 4 hours = “Treat Level”)
address the associated N/V that may develop w/NAC
Metoclopromide
What does effect does aspirin OD have on body?
metabolic acidosis (uncouple oxidative phosphorylation —> ↑pyruvate converted to lactic acid —> Metabolic Acidosis)
w/ compensatory respiratory alkalosis
Aspirin follow (0, 1st) order elimination
zero
presentation of moderate ASA intx
inc HR, RR, tinnitus
management of ASA intox
- activated charcoal
- glc
- NaHCO3 **alkalizes urine and traps ASA + K to avoid depletion
- hemodiaysis in severe cases
MOA cyproheptadine
H1 antagonist w/ anti-serotonin properties (acts on GI sm muscle and CNS)
MOA cyanide damage
inhibits ETC cytochrome oxidase —> ↓ aerobic = ↑ anaerobic glycolysis for ATP
What drugs are in a cyanide kit
Sodium Nitrate + Sodium Thiosulfate + Amyl Nitrite
key symptom is smell of rotten eggs;
Hydrogen sulfide intox
methemoglobinemia is assc w/ intox w/
cyanide and nitrous oxide
Myocardium: ↑sensitization to catecholamines
Local Reaction: burning sensation in mouth, perioral rash, pruritis
)Organ Systems: hepato/renal toxicity
hydrocarbon intox
inhibits AcH-ase via phosph /carbamoylation —> ↑Cholinergic (MUDPILES)
Insecticides ~ Organophosphates (Malathion)
Carbamates (Carbafuran)
Nerve Gases (Sarin, Soman, VX)
Antidote for organophosphates (Malathion) + Carbamates (Carbafuran) + Nerve Gases (Sarin, Soman, VX) intox
Atropine (↓cholinergic effect)
Pralidoximine = Protopam (2PAM) (↑AcH-ase activity)
botanical insecticide that inhibits post-synaptic nicotinic-R —> stimulation then depolarization block —> seizures
Nicotine
botanical that acts on Na/Ca/Cl voltage sensitive channels —> seizures/tetanus + contact dermatitis
Pyrethrum
Botanical insecticide that when ingested causes > Gi irritation + dermatitis
Rotenone
Intoxication with ____ causes: GI > pulmonary —> breath odor + vomiting/diarrhea —> metabolic acidosis + ↑CK/Myoglobinuria
What is treatment?
2,4-Dichlorophenoxyacetic Acid (2,4-D)
electrolytes + NaHCO3 to allkalize urine
intoxication with ___ causes acute swelling of mouth/throat + blood diarrhea —> slow onset organ failure (lung)
How does it cause damage
Paraquat
inc free radicals
diff in damage done by acid vs base
acid = coagulation necrosis base = liquifactive necrosis
inhibits heme synthesis (ALA dehydratase + ferrochelatase) —> ↑protoporphyrin
Lead
effects of lead poisoning on various organs
L-E-A-D
(1) Lines: Burton’s Lines + Bones
(2) Encephalopathy: xPKC + ∆neuroTx
(3) Anemia + Acute Kidney / GI
- GI: ↓AcH release + Na/K ATPase inhibition —> ↓motility + water flux —> colic/constipation
- Kidney: ↓PT function —> aminoaciduria + glycosuria + hypophosphaturia
(4)“Drop” (wrist): ↓Neve Conduction w/ Schwann cell destruction —> demyelination / axonal degradation
treatment of mild and severe lead poisoning
Succimer (DMSA ~ Mild), Dimercaprol (severe), EDTA
**NOTE: Blood Levels: drop w/chelation —> rise again b/c lead redistributes from tissue w/↓blood concentration
what can you use to measure exposure to arsenic?
HAIR
**∆pigmentation/keratoses
causes interstitial pneumonitis (w/vapor exposure) + intension tremor + gum inflammation w/↑salivation
+skin dequamation in kids
+paresthesia around mouth
Mercury poisoning
effect of Mercury poisoning on kidneys
ATN + nephrotic syndrome
hematemesis + diarrhea (hypovolemic shock) —> eventual liver failure
Iron intoxication
mech of damage in iron intox
dec oxidative phosphorylation in mito
endothelial damage —> platelet aggregation —> RBC lysis —> small vessel necrosis + occlusion
–> pruritis + growing blister +/- loxoscelism develops
brown recluse venom
cramping —> systemic symptoms —> fatality (rare)
Black widow venom
Tx of spasms w/ black widow bite
BNZ
