Exam 3 Toxicology Flashcards Preview

Pharm II > Exam 3 Toxicology > Flashcards

Flashcards in Exam 3 Toxicology Deck (38):
1

4 areas of study in toxicology

1. occupation safety
2. environmental toxicology
3. analytic toxicology
4. forensic toxicology

2

term describing the range of response per dose, an individual may require a higher/lower dose to produce the desired effect

biological variation

3

term describing a greater than normal reaction to a drug

hypersusceptibility

4

term describing the response of the patient to the drug when it is qualitatively different from the usual or expected response

drug idoiosyncrasy

5

Geriatric patients have less ___ ___ (decreased plasma proteins), less _____ (decreased liver function) and decreased renal function which allows for normal doses of drugs to act at ____ levels. Give ___ dose

binding capacity
metabolism
overdose
lower

6

In a pt with liver disease, drug ___ is reduced due to diminished function of ____ ____ system, dosing must be reduced.

metabolism
cytochrome P450

7

In a pt with renal disease, renal impairment of ___ ___ occurs, dosing must be modified on the basis of renal ____ ___ of the drug

drug excretion
clearance values

8

___ ____: increasing amounts of drug are required to produce a consistent effect, usually associated with drugs that cause ____ ____.

drug tolerance
physical dependence

9

____: rapid development of tolerance

tachyphylaxis

10

what does TD50/ED50 mean?

Therapeutic index
TD50 = dose of the drug that causes a toxic response in 50% of the popultion
ED50 = dose of the drug that is therapeutically effective in 50% of the population

11

The therapeutic index provides a single number that quantifies the relative ____ of ___ of a drug in population of people. A large Ti represents a ___ therapeutic window and a small TI represents a ___ therapeutic window = requires monitoring

margin of safety
wide
narrow

12

____ toxicity occurs as a result of a single, large ___ to the toxic agent. Effects are usually ____ within minutes to hours. Occasionally, signs of acute toxicity are not visible for ___ to ___ following the initial exposure.

Acute
exposure
visible
weeks to months

13

____ toxicity = the effect of toxic insult that occurs over a ____ period of time. Often it is manifested after ___ of exposure. May also manifest long after the individual is no longer exposed to the ____.

Chronic
prolonged
years
toxin

14

Study of the absorption, distribution, metabolism, and excretion of toxic parent compounds and metabolic products

toxicokinetics

15

4 types of GI toxins

1. ingested
2. contaminants in food (mercury in fish)
3. majority of therapeutic agents (drugs)
4. lead in dirt and paint

16

4 types of inhaled toxins

1. air pollutants
2. cigarette smoking
3. industrial chemicals
4. agents of chemical warfare

17

What toxin can passively diffuse through the 7 layers of skin after prolonged contact?

insecticides

18

8 mechanism of toxicity

1. Interference with cellular function
2. Macromolecular damage
3. Reactive species
4. inflam/immune mediated mechanisms
5. Enzyme/receptor mediated
6. Carcinogenesis
7. Teratogenesis
8. Organ directed toxicity

19

What type of toxicity mechanism is described: carbon monoxide binds strongly to the iron in the active site of hemoglobin, preventing oxygen binding and reducing oxygen carrying capacity.

Receptor mediated

20

What type of toxicity mechanism is described: nerve gasses/pesticides are acetylcholinesterase inhibitors which causes excessive concentration of ach in synaptic cleft resulting in slowed HR, difficulty breathing, sweating, pinpoint pupils

Enzyme mediated (common toxins interfere with NT, cardiac rhythm, oxygen deliver, ATP generation, or intracellular ca balance)

21

What type of toxicity mechanism is described: cyanide binds to the heme iron in the active site of the enzyme cytochrome C oxidase causing reduction in the generation of ATP

Enzyme mediated (many compounds are toxic bc they alter important metabolic pathways, signaling pathways, or interact with critical receptors)

22

What type of toxicity mechanism is described: toxins damage tissue by altering the structure of proteins, lipids, carbs, and nucleic acids so severely that cellular integrity is lost

macromolecular damage - tissue damaging agents are nonspecific

23

What type of toxicity mechanism is described: React chemically with biologic macromolecules and other chemicals, more specific in their site of action, example: carbon tetrachloride

Reactive species - when carbon tetrachloride is metabolized by the liver, reacts with oxygen to form toxic organic free radicals which cause toxicity

24

What type of toxicity mechanism is described: hypersensitivity and autoimmune reactions

Inflammatory and immune mediated mechanisms - the immune system removes cell damaged by toxins and releases immune mediators that are important in repairing tissue damage

25

What type of toxicity mechanism is described: the transformation of a normal cell to a neoplastic cell

carcinogenesis - involves multiple genetic changes

26

Development of cancer: Initiators damage ____, interfere with DNA replication or ___ mechanisms. Most initiators are ___ ___ that chemically modifies the structures of DNA, preventing accurate ____ which causes DNA _____. Mutations are passed along during cell ____.

DNA
repair
reactive species
replication
mutation
replication

27

Carcinogens can also promote the development of cancer by causing what?

chronic tissue damage in organs capable of tissue repair (alcoholism -> cirrhosis -> liver cancer)

28

What type of toxicity mechanism is described: substances that can inhibit intracellluar signals are potent, they can induce a birth deft and also alter DNA or chromosomes

Teratogenesis - effect of any substance is dependent on the development timing of the exposure

29

What type of toxicity mechanism is described: organs with regenerative capacity may recover after toxic exposure and organs with limited or no regenerative function lose function as tissue is destroyed from toxic exposure (heart/nerves)

Organ directed toxicity - blood brain barrier prevents many toxins from entering the CNS

30

3 mechanisms of selected toxicity by drugs
1. Attack targets that are unique to the pathogen but are not ______
2. Attack target in the pathogen or cancer cell that are similar ___________
3. Attack targets in the pathogen/cancer cell that are shared _________

1. present in the host
2. but not identical to those in the host
3, by the host but that vary in importance between pathogen and the host

31

Drugs exhibit the ____ toxicity when they target a ___ ___ between the pathogen and host cell
Drugs exhibit the ___ toxicity when they target ___ ___ shared by both the pathogen and the host cell.

Least
unique difference
most
common pathway

32

A highly ___ drugs like penicillin is prescribed ___ because of the large difference between the therapeutic and ___ concentrations.Drugs that are less selective means that they affect both the pathogen and host cells and are ___ ___ and have a ____ therapeutic index.

selective
safely
toxic
not safe
narrow

33

4 examples of unique targets (present in pathogen bu lacking in host)

1. metabolic pathways
2. enzymes
3. mutated genes
4. gene products

34

_______: when the host and the pathogen share a common biochemical or physiologic pathway

Common targets - narrow therapeutic index

35

With common targets their are adverse side effects, name 5

1. loss of hair
2. mouth sores
3. skin problems
4. GI problems
5. infertility

36

drugs that affect only 1 phase of the cell cycle

cell cycle specific

37

drugs that affect any/all phases of the cell cycle

cell cycle non specific (most antineoplastic drugs affect either S or M phase)

38

3 phases of carcinogenesis

1.transformation
2. proliferation
3. metastasis