Exam 12: Environmental Toxicology and Antidotes

Question 1

NOAEL

Answer 1

No Observed Adverse Effect Level: Highest dose that doesn’t produce a statistically significant toxic effect

Question 2

RfD

Answer 2

Reference Dose: Estimated daily exposure that is assumed to have no adverse health impact on the human population

Question 3

6 Common causes of anticholinergic toxicity

Answer 3

1. Atropine
2. Scopolamine
3. Antihistamines
4. Antiparkinson’s (amantidine)
5. Antipsychotics
6. Plants (Belladonna)

Question 4

Treatment for anticholinergic poisoning

Answer 4

Physostigmine

Question 5

Treatment for seizures caused by too much of a stimulant

Answer 5

Benzos

Question 6

Treatment for tachycardia caused by too much of a stimulant

Answer 6

Lidocaine

Question 7

Treatment for ventricular fibrillation caused by too much of a stimulant

Answer 7

Lidocaine

Question 8

Treatment for opioid toxicity

Answer 8

Naloxone

Question 9

Treatment for Cholinergic syndromes

Answer 9

Cholinergic antagonist like Atropine

Pralidoxime is only used for Organophosphate poisoning

Question 10

Mechanism of activated charcoal. Limitation?

Answer 10

Non-specific chelator that limits drug absorption

Doesnt work as well if a drug is rapidly absorbed

Question 11

Use of Whole-bowel irrigation (actual substance that is used)

Answer 11

Non-absorbable polyethylene glycol

Used after large ingestion of drugs that are poorly absorbed by activated charcoal

Question 12

Difference between organophosphates and carbamate insecticides

Answer 12

Carbamates are reversible acetylcholinesterase inhibitors (treat with atropine only)
Organophosphates are irreversible (Treat with atropine and pralidoxime)

Question 13

Chlorinated insecticides mechanism

Answer 13

Inhibit voltage-gated Na+ channels, leading to seizures, tremors, weakness, twitches, etc.

Question 14

2 Treatments for Chlorinated insecticides (DDT)

Answer 14

1. Activated charcoal/gastric lavage

2. Anticonvulsants (slowly infused)

Question 15

Pyrethrins symptoms and treatments (2)

Answer 15

Bronchospasm, numbness, seizures

1. Charcoal/lavage
2. Bronchodilators for bronchospasm

Question 16

Problem with methanol

Answer 16

Metabolized to formaldehyde by alcohol dehydrogenase (blindness, metabolic acidosis)

Question 17

Methanol treatments (2)

Answer 17

1. Treat acidosis with bicarb

2. Fomepizole (Alcohol dehydrogenase inhibitor)

Question 18

2 consequences of Ethylene glycol ingestion

Answer 18

1. Hypocalcemic tetany

2. Oxalicaciduria - crystals

Question 19

2 treatments for Ethylene glycol poisoning

Answer 19

1. Calcium for their hypocalcemia

2. Fomepizole

Question 20

Result of Diethylene glycol poisoning (treatment)

Answer 20

Anuric renal failure

Supportive/symptomatic care

Question 21

Sources of lead poisoning

Answer 21

1. Food/water
2. Dust
3. Paint chips

Question 22

4 effects of lead poisoning

Answer 22

1. Microcytic anemia
2. Weak wrist and ankle extensors
3. Lead encephalopathy
4. Colic loss of apatite

Question 23

First and second line treatments for severe lead poisoning

Answer 23

1. Succorer

2. EDTA

Question 24

Treatment for cerebral edema in lead poisoning

Answer 24

Dexamethasone

Question 25

Why are children most at risk of lead poisoning?

Answer 25

They absorb up to 40% of that ingested, adults only 10%

Question 26

2 effects of lead on kids

Answer 26

1. Deteriorates their BBB | 2. Low IQ, ADHD, behavior problems

Question 27

Arsenic poisoning source

Answer 27

Rural/municipal water supplies

Question 28

Arsenic acute intoxication signs/symptoms

Answer 28

Hemorrhagic gastroenteritis | Garlic odor on breath

Question 29

Arsenic chronic intoxication signs/symptoms

Answer 29

Hyperkeratosis, exfoliative dermatitis

Question 30

Arsenic poisoning mechanism

Answer 30

Binds to -SH groups on proteins and causes severe oxidative stress

Question 31

Arsenic toxicity treatment

Answer 31

Dimercaprol

Question 32

Treatment for inhalation of arsenic gas

Answer 32

This only occurs in miners | Supportive therapy only

Question 33

Methylmercury sources

Answer 33

Gold mining Fish Grain fungicide

Question 34

Signs and symptoms of mercury poisoning

Answer 34

Ataxia, loss of balance, sensory defects, visual defects, deafness, dysarthria THESE ARE ALL IRREVERSIBLE

Question 35

Who should avoid eating predatory fish?

Answer 35

Pregnant women | Canned tuna is probably safe though

Question 36

Mercury in cavity fillings

Answer 36

They pose little hazard | Dentists ARE NOT supposed to advocate their removal

Question 37

When is chelation therapy used

Answer 37

Severely elevated metal levels or toxicity

Question 38

Chelation therapy consideration

Answer 38

Only reduces readily accessible pool of metal. After therapy, blood levels of the metal can rebound

Question 39

Edentate Calcium Use, Side effects, tocixity

Answer 39

EDTA 1. Lead poisoning antidote 2. Chills, fever, nausea voliting 3. Nephrotoxic at high dose

Question 40

Penicillamine use

Answer 40

Wilson's disease | also for lead poisoning

Question 41

Succimer use, advantage

Answer 41

First orally effective chelator | Works faster than EDTA in lead poisoning

Question 42

First sign of CO poisoning

Answer 42

Headache

Question 43

CO poisoning treatment

Answer 43

Hyperbaric O2

Question 44

Treatment for cyanide toxicity

Answer 44

Hydroocobalamin | Reacts to form vitamin B12

Question 45

Asbestos antidote

Answer 45

There isn't one | Dont get exposed

Question 46

PCBs and Dioxin signs and symptoms

Answer 46

Chloracne, nausea, vomiting, headache

Question 47

Dioxin treatment

Answer 47

None!!

Question 48

Bisphenol A (BPA)

Answer 48

Leached from plastic into food and water | Exposure in utero MAY be linked to neural and behavioral defects