Toxicology

Question 1

2 drugs used for gastric decontamination + how they work

Answer 1

activated charcoal = toxin abs ans excreted in feces **only good w/in 1 hr
Ipecac = emetic **only good w/in 30 mins

Question 2

main problem with charcol

Answer 2

vomit charcoal –> aspirate –> death

Question 3

main problems with Ipecac

Answer 3

1. abused w/ eating disorders

2. electrolyte imbalance; cardiotoxicity

Question 4

type of toxin that can be removed with hemodialysis

Answer 4

water soluble toxins that are NOT highly protein bound

Question 5

How do you remove toxins that are highly protein bound?

Answer 5

hemoperfusion (blood pass thru charcol filter)

Question 6

Examples of drugs that are removed by hemoperfusion

Answer 6

Phenytoin, Barbs, Carbamazapine, Theophylline

Question 7

β Blocker w/out ɑ Blocker is CI in the treatment of sympathomimetic OD bc…

Answer 7

unopposed ɑ receptor action –> HTN crisis

Question 8

describe the phases of acetaminophen toxicity

Answer 8

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

Question 9

do NOT stop NAC once started; complete 1 Loading Dose + (#) Maintenance Doses

Answer 9

17

Question 10

What is acetaminophen “risk line”

Answer 10

(~150 ug/mL @ 4 hours = “Treat Level”)

Question 11

address the associated N/V that may develop w/NAC

Answer 11

Metoclopromide

Question 12

What does effect does aspirin OD have on body?

Answer 12

metabolic acidosis (uncouple oxidative phosphorylation —> ↑pyruvate converted to lactic acid —> Metabolic Acidosis)

w/ compensatory respiratory alkalosis

Question 13

Aspirin follow (0, 1st) order elimination

Answer 13

zero

Question 14

presentation of moderate ASA intx

Answer 14

inc HR, RR, tinnitus

Question 15

management of ASA intox

Answer 15

1. activated charcoal
2. glc
3. NaHCO3 **alkalizes urine and traps ASA + K to avoid depletion
4. hemodiaysis in severe cases

Question 16

MOA cyproheptadine

Answer 16

H1 antagonist w/ anti-serotonin properties (acts on GI sm muscle and CNS)

Question 17

MOA cyanide damage

Answer 17

inhibits ETC cytochrome oxidase —> ↓ aerobic = ↑ anaerobic glycolysis for ATP

Question 18

What drugs are in a cyanide kit

Answer 18

Sodium Nitrate + Sodium Thiosulfate + Amyl Nitrite

Question 19

key symptom is smell of rotten eggs;

Answer 19

Hydrogen sulfide intox

Question 20

methemoglobinemia is assc w/ intox w/

Answer 20

cyanide and nitrous oxide

Question 21

Myocardium: ↑sensitization to catecholamines
Local Reaction: burning sensation in mouth, perioral rash, pruritis
)Organ Systems: hepato/renal toxicity

Answer 21

hydrocarbon intox

Question 22

inhibits AcH-ase via phosph /carbamoylation —> ↑Cholinergic (MUDPILES)

Answer 22

Insecticides ~ Organophosphates (Malathion)
Carbamates (Carbafuran)
Nerve Gases (Sarin, Soman, VX)

Question 23

Antidote for organophosphates (Malathion) + Carbamates (Carbafuran) + Nerve Gases (Sarin, Soman, VX) intox

Answer 23

Atropine (↓cholinergic effect)

Pralidoximine = Protopam (2PAM) (↑AcH-ase activity)

Question 24

botanical insecticide that inhibits post-synaptic nicotinic-R —> stimulation then depolarization block —> seizures

Answer 24

Nicotine

Question 25

botanical that acts on Na/Ca/Cl voltage sensitive channels —> seizures/tetanus + contact dermatitis

Answer 25

Pyrethrum

Question 26

Botanical insecticide that when ingested causes > Gi irritation + dermatitis

Answer 26

Rotenone

Question 27

Intoxication with ____ causes: GI > pulmonary —> breath odor + vomiting/diarrhea —> metabolic acidosis + ↑CK/Myoglobinuria
What is treatment?

Answer 27

2,4-Dichlorophenoxyacetic Acid (2,4-D)

electrolytes + NaHCO3 to allkalize urine

Question 28

intoxication with ___ causes acute swelling of mouth/throat + blood diarrhea —> slow onset organ failure (lung)

How does it cause damage

Answer 28

Paraquat

inc free radicals

Question 29

diff in damage done by acid vs base

Answer 29

acid = coagulation necrosis
base = liquifactive necrosis

Question 30

inhibits heme synthesis (ALA dehydratase + ferrochelatase) —> ↑protoporphyrin

Answer 30

Lead

Question 31

effects of lead poisoning on various organs

Answer 31

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

Question 32

treatment of mild and severe lead poisoning

Answer 32

Succimer (DMSA ~ Mild), Dimercaprol (severe), EDTA

**NOTE: Blood Levels: drop w/chelation —> rise again b/c lead redistributes from tissue w/↓blood concentration

Question 33

what can you use to measure exposure to arsenic?

Answer 33

HAIR

**∆pigmentation/keratoses

Question 34

causes interstitial pneumonitis (w/vapor exposure) + intension tremor + gum inflammation w/↑salivation
+skin dequamation in kids
+paresthesia around mouth

Answer 34

Mercury poisoning

Question 35

effect of Mercury poisoning on kidneys

Answer 35

ATN + nephrotic syndrome

Question 36

hematemesis + diarrhea (hypovolemic shock) —> eventual liver failure

Answer 36

Iron intoxication

Question 37

mech of damage in iron intox

Answer 37

dec oxidative phosphorylation in mito

Question 38

endothelial damage —> platelet aggregation —> RBC lysis —> small vessel necrosis + occlusion

–> pruritis + growing blister +/- loxoscelism develops

Answer 38

brown recluse venom

Question 39

cramping —> systemic symptoms —> fatality (rare)

Answer 39

Black widow venom

Question 40

Tx of spasms w/ black widow bite

Answer 40

BNZ