Intro to Toxicology

Question 1

What is toxicology?

Answer 1

the study of adverse effects of chemical, biological, and physical agents on living systems

Question 2

What are toxins?

Answer 2

toxic substances produced by biological systems such as plants and animals

Question 3

What are toxicants?

Answer 3

toxic substances produced by human activities

Question 4

What is toxidrome?

Answer 4

term for “toxicologic syndromes” - a group of signs and symptoms consistently associated with specific toxic agents

Question 5

What is risk?

Answer 5

the expected frequency of the occurrence of an undesirable effect arising from exposure to a chemical or physical agent

Question 6

What is hazard?

Answer 6

the ability of a chemical agent to cause injury in a given situation or setting

Question 7

What is acute exposure?

Answer 7

a single exposure, or multiple exposures occurring over 1-2 days.

Question 8

What is chronic exposure?

Answer 8

continuous of multiple exposures occurring longer than a few days

Question 9

What are synergistic effects?

Answer 9

a greater than additive effect from exposure to two or more chemicals

Question 10

What is potentiation?

Answer 10

a special form of synergism; when a chemical that itself produces no effect increases the toxicity of another.

Question 11

What is therapeutic index?

Answer 11

ratio between the toxic dose and therapeutic dose of a drug

Question 12

Example of very potent drug? What does this mean?

Answer 12

Botulinum toxin. lower dose is lethal.

Question 13

example of less potent drug?

Answer 13

ethyl alchol. less potent but can still be lethal.

Question 14

what’s important to note about dose and potency?

Answer 14

wide range, but all can be used safely. need to know dose AND potency to determine toxicity.

Question 15

Where do we get info about toxicities (4)?

Answer 15

human studies, animal studies, in vitro studies, computer modeling

Question 16

What should you be concerned with when treating poisoning?

Answer 16

ABC’s

Question 17

What is the quick fix for hypoglycemia?

Answer 17

Dextrose

Question 18

What is the quick fix to prevent Wernicke’s encephalopathy?

Answer 18

Thiamine

Question 19

What is the quick fix opioid antagonist?

Answer 19

Naloxone

Question 20

What is the quick fix benzodiazepine antagonist?

Answer 20

Flumazenil

Question 21

what are some labs you should look at?

Answer 21

arterial blood gases, electrolytes, renal function, serum osmolality, ECG

Question 22

What’s up with screening?

Answer 22

there are screening tests for certain classes of chemicals. broad screening is time-consuming, expensive, and generally ineffective. but specific measurements can be important in determining therapeutic approach and prognosis

Question 23

how to decontaminate GI tract (5)?

Answer 23

1) emesis: syrup of ipecac
2) gastric lavage: risk vs. benefit?
3) activated charcoal: sometimes contraindicated
4) cathartics: can be given with charcoal to hasten elimination from bowel
5) whole bowel irrigation: oral solution, drug packers

Question 24

4 ways to enhance elimination?

Answer 24

urinary pH manipulation (only works for a few chemicals), peritoneal dialysis (simple but inefficient), hemodialysis (more efficient), hemoperfusion (can remove low water solubility drugs)

Question 25

3 mechanisms of antidotes?

Answer 25

1) bind to toxicant and inactivate it (e.g. chelators, antibody fragments for digoxin)
2) block critical receptors (e.g. naloxone, atropine for anticholinesterase agents)
3) change toxicant metabolism (e.g. ethanol for methanol, NAC for acetaminophen)