Toxicology Pharm

Question 1

bioaccumulation

Answer 1

increasing conc of a substance in the environment resulting from environmental persistence and physical properties (chemically stable, resistant to metabolism and lipid soluble) leading to accumulation in biological tissues

Question 2

biomagnification

Answer 2

fold increase in concentration of a substance that occurs in a food chain as a consequence of bioaccumulation

Question 3

tx for CO poisoning

Answer 3

100% oxygen and hyperbaric oxygen

Question 4

benzene and toluene

Answer 4

acute exposure –> CNS depression w/ ataxia and coma
chronic exposure –> neuro and bone marrow toxicity, leukemia
inhalation –> chemical pneumonitis

Question 5

why is the root of exposure important in gasoline poisoning?

Answer 5

in ingestion, care must be taken to avoid inducing vomiting
aspiration w/ vomitus can cause fatal chemical pneumonia

LD is much lower in the lung that in GIT

Question 6

toxic effects of chlorinated hydrocarbons (DTT, DDD, dioxin)

Answer 6

chlorine confers environmental stability
moderately toxic, bioaccumulation, leads to endocrine disruption
no specific tx

Question 7

toxic effects of carbamates and organophosphates

Answer 7

carbaryl, malathion, parathion
less stable than chlorinated pesticides
muscarinic and nicotinic activators –> SLUDGE sx
tx: atropine blocks receptor activation + pralidoxine to regenerate cholinesterase

Question 8

lead poisoning toxic effects

Answer 8

acute poisoning –> abdominal colic and CNS changes
chronic poisoning –> peripheral neuropathy, anorexia, anemia, tremor, GI symptoms
+ children growth delays, neurocog defects, developmental delay
lead-line on gums in 50-70%, basophilic stippling of RBCs

Question 9

what tx prefered to tx lead toxicity in children?

Answer 9

oral succimer

Question 10

arsenic poisoning sx

Answer 10

acute: severe GI discomfort, rice water stools, vomiting, capillary damage w/ dehydration and shock (like typhoid and cholera)
chronic: skin damage, hair loss, bone marrow depression, anemia, nausea and GI disturbances

Question 11

causes of arsenic poisoning

Answer 11

usually from environmental water (wells)

Question 12

Mee’s lines

Answer 12

transverse white lines across the nail from ARSENIC poisoning

Question 13

mercury toxicity

Answer 13

acute: chest pain, SOB, nausea, vomiting, kidney damage, gastroenteritis, CNS damage
chronic: sore gums and teeth, GI disturbance, neurological and behavioral changes (mad hatter)
fetal toxic

Question 14

common cause of mercury toxicity

Answer 14

used as an anti fungal agent and can bioaccumulate

Question 15

iron toxicity sx

Answer 15

vomiting, GI bleeding, lethargy, grey cyanosis –> severe GI necrosis, pneumonitis, jaundice, seizure, comas

Question 16

tx for iron toxicity

Answer 16

CHARCOAL DOES NOT BIND IRON
use gastric lavage w/in 60 min, whole bowel irrigation w/ polyethylene glycol bowel prep if longer than 60 min
chelating agent: deferoxamine

Question 17

how do chelators work

Answer 17

for a “chemical cage” to sequester metal ions
have 2 or more electronegative grows that complex cations (bidentate or polydentate)

don’t reverse damage, only prevent further damage

Question 18

treating poisoned patients - basics

Answer 18

ABCDs:
Airway
Breathing
Circulation
Dextrose: for pts w/ altered mental status

Question 19

tx for acetaminophen tox

Answer 19

activated charcoal w/in 1-2 hrs if possible

N-acetylcysteine w/in 8-10 hrs

Question 20

tx for aspirin toxicity

Answer 20

IV sodium bicarb

severe cases: hemodialysis

Question 21

tx for methanol, ethylene glycol toxicity

Answer 21

fomepizole - competes for alcohol dehydrogenase

Question 22

tx for benzodiazepine toxicity

Answer 22

flumazenil - blocks site of benzo action

Question 23

tx for beta-blocker toxicity

Answer 23

glucagon - acts on cardiac cells to raise intracellular cAMP independently of beta-adrenoceptors

Question 24

how does NAC work?

Answer 24

increases glutathione stores –> combines directly w/ acetaminophen’s reactive metabolite

Question 25

toxic effects of aspirin

Answer 25

respiratory alkalosis + AG metabolic acidosis

hyperapnea, hyperthermia, tinnitus