9.16.2022. IS questions

Question 1

list 5 targets of selective toxicity of antimicrobial drugs

Answer 1

the Great Wall. wall, mortar, pathway.

1. cell wall
2. nucleic acid synthesis
3. cell membrane integrity
4. metabolic pathways (foliate biosynthesis)
5. protein synthesis

Question 2

which would be safer, a drug with a therapeutic index of 2 or one with a therapeutic index of 100?

Answer 2

100. the higher, the safer.

Question 3

describe a situation when a bactericidal drug would be more appropriate than one that is bacteriostatic, i.e. when would i want one or the other?

Answer 3

bactericidal: kills bacteria. useful when host defenses cannot be relied on to eliminate pathogens

bacteriostatic: inhibits
bacterial growth. must rely on body’s defense system to kill or eliminate the pathogen after growth has been stopped.

Question 4

describe a situation when a broad-spectrum drug would be most suitable

Answer 4

• affect wide range of bacteria, include G+ and G- organisms
• important for treating acute life-threatening diseases when immediate antimicrobial treatment is essential and there’s not time to culture and identify the pathogen

Question 5

in what situation does a physician have to choose a high toxicity drug?

Answer 5

if lower toxicity drugs haven’t worked

Question 6

describe the benefits of a drug that has a longer half-life versus a drug that has a shorter one?

Answer 6

determines how often you need to take medicine (every four hours vs. every twenty-four hours, for instance)

Question 7

what is antibiotic-associated colitis?

Answer 7

• normally, C. difficile cannot establish itself in the intestine due to competition from other bacteria
• sometimes though, when people take broad-spectrum antimicrobials orally, they develop diarrheal disease caused by C. difficile
• when the microbe is disrupted, C. difficile can sometimes grow to high numbers, cause intestinal damage, which results in symptoms that range from mild diarrhea to life-threatening colitis

Question 8

what is dysbiosis?

Answer 8

an imbalance in the microbiome

Question 9

mycoplasma species are intrinsically resistant to penicillin. why?

Answer 9

no cell wall! penicillin affects peptidoglycan, which is found in the cell wall

Question 10

how to measure therapeutic index?

Answer 10

( lowest dose toxic to the patient ) / ( dose used therapeutically )

Question 11

what does bactericidal mean?

Answer 11

an antimicrobial medication that kill bacteria

Question 12

what does bacteriostatic mean ?

Answer 12

an antimicrobial medication that inhibits bacterial growth

Question 13

what is the disadvantage of broad-spectrum antibiotics?

Answer 13

by affecting a wide range of bacteria, they also disrupt the microbiome. this puts the patient at risk for developing other infections.

Question 14

describe a situation when a narrow-spectrum drug would be most suitable

Answer 14

• limited range of bacteria, like only G+
• less disruptive to the microbiome

Question 15

use of a narrow-spectrum antibiotic depends on what?
how might a patient be treated using this information?

Answer 15

• the antimicrobial susceptibility of the pathogen
• patient may be started on broad-spectrum and then switched to narrow-spectrum later, once the relevant information has been determined

Question 16

therapeutic index and toxicity
high therapeutic index = ?

Answer 16

less toxic

Question 17

therapeutic index and toxicity
low therapeutic index = ?

Answer 17

high toxicity

Question 18

therapeutic index and toxicity
more toxicity = ?

Answer 18

lower therapeutic index

Question 19

therapeutic index and toxicity
less toxicity = ?

Answer 19

high therapeutic index

Question 20

what may be a cause of dysbiosis

Answer 20

may be caused by taking antimicrobial medications