Chapter 5

Question 1

minimizes the development of resistance as well as resulting in a therapeutically successful
outcome

Answer 1

successful antimicrobial therapy

Question 2

Effective antimicrobial therapy depends on

Answer 2

1. Susceptibility of the pathogen
2. Pharmacokinetic characteristics of the drug
3. Amount of drug given at one time
4. Route, frequency of administration and the duration of treatment

Question 3

Other variables relating to chemotherapy

Answer 3

1. Toxicity of the drug for the host
2. Its half-life
3. Concentration and persistence at the site of infection
4. its effect on the normal flora of the host

Question 4

most useful of the classifications of antimicrobial drugs

Answer 4

mechanism of action

Question 5

narrow- spectrum because they inhibit only bacteria

Answer 5

penicillin

Question 6

broader because they inhibit both bacteria and protozoa

Answer 6

1. sulfonamides
2. trimethoprim
3. lincosamides

Question 7

only inhibit fungi

Answer 7

Polyenes

Question 8

antibiotics that are narrow spectrum in that they inhibit only gram-positive

Answer 8

1. bacitracin
2. vancomycin

Question 9

mainly inhibit gram negative bacteria

Answer 9

Polymyxin

Question 10

broad spectrum drugs that inhibit both gram- positive and gram-negative bacteria

Answer 10

Tetracycline

Question 11

most active against gram-positive bacteria but will inhibit some gram-negatives

Answer 11

Penicillin G, Lincosamides

Question 12

Mechanism of Action of Antimicrobial drugs

Answer 12

1. inhibition of cell wall synthesis
2. damage to cell membrane function
3. inhibition of nucleic acid synthesis or function
4. inhibition of protein synthesis

Question 13

Inhibition of Cell Wall Synthesis

Answer 13

1. Penicillin
2. cephalosporins (β-lactam antibiotics)
3. bacitracin
4. vancomycin.

Question 14

gives the cell wall remarkable strength

Answer 14

cross-linkage between peptidoglycans

Question 15

Antibiotics that damage cell membrane function

Answer 15

1. polymyxins
2. monensin
3. antifungal polyenes (amphotericin, nystatin)
4. imidazoles (fluconazole, itraconazole, ketoconazole, miconazole)

Question 16

Drugs with greater selective toxicity which inhibit the synthesis of folic acid

Answer 16

Sulfonamides and trimethoprim

Question 17

drugs that inhibit nucleic acid function

Answer 17

1. nitroimidazoles
2. nitrofurans
3. nalidixic acid
4. fluoroquinolones
5. Novobiocin
6. Rifampin
7. sulfonamides
8. trimethoprim
9. 5-flflucytosine.

Question 18

Aminoglycosides

Answer 18

amikacin, gentamicin, kanamycin, neomycin, streptomycin, tobramycin

Question 19

aminocyclitols

Answer 19

spectinomycin

Question 20

lincosamides

Answer 20

clindamycin, lincomycin

Question 21

macrolides

Answer 21

azithromycin, clarithromycin, erythromycin, tylosin, tiamulin

Question 22

Affect 30s ribosomes

Answer 22

tetracyclines, aminoglycosides, aminocyclitols

Question 23

affect 50s ribosomes

Answer 23

chloramphenicol, macrolides, lincosamides

Question 24

combined action is no greater than that of the more effective drug used alone

Answer 24

indifference

Question 25

combined action is equivalent to the sum of the actions of each drug when used alone

Answer 25

additive

Question 26

combined action is significantly greater than the sum of both effect

Answer 26

synergism

Question 27

combined action is less than that of the more effective agent when used alone

Answer 27

antagonism

Question 28

Forms of antimicrobial synergy

Answer 28

1. Two drugs may sequentially block a microbial metabolic pathway 2. One drug may prevent the inactivation of a second drug by microbial enzymes 3. One drug may promote the uptake of a second drug thereby increasing the overall antimicrobial effect 4. One drug may affect the cell membrane and facilitate the entry of a second drug 5. A drug combination may also prevent the emergence of resistant populations

Question 29

Considerations when administering two antimicrobial drugs

Answer 29

1. Drugs are not antagonistics to each other 2. Treatment of mixed bacterial infections, where each drug has activity against one of the pathogens 3. Treatment of severe infections of uncertain aetiology 4. Use of synergistic combinations with documented efficacy against specific infections

Question 30

threatens the effective prevention and treatment of an ever-increasing range of infections caused by bacteria, parasites, viruses and fungi

Answer 30

AMR

Question 31

medicines used to prevent and treat infections in humans, animals and plants

Answer 31

antimicrobials

Question 32

develop antimicrobial resistance

Answer 32

superbugs

Question 33

bacterial cells that are not susceptible to the drug, but do not possess resistance genes

Answer 33

persistence

Question 34

minimal concentration of drug that will inhibit growth of the bacteria

Answer 34

Minimum Inhibitory Concentration

Question 35

genes are naturally occurring in the bacteria, but are only expressed to resistance levels after exposure to an antibiotic

Answer 35

induced

Question 36

resistance always expressed in the species

Answer 36

intrinsic

Question 37

shared universally within a bacterial species, is independent of previous antibiotic exposure

Answer 37

intrinsic resistance