Antimicrobial Drugs

Question 1

A low molecular substance produced by a microorganism that inhibits or kills other microorganisms causing little or no damage to itself is called what?

Answer 1

Antibiotic

Question 2

Any substance (synthetic or natural) that kills or inhibits the growth of microorganisms while causing little or no damage to itself is called what?

Answer 2

Antimicrobial

Question 3

________ drugs are active against a wide range of microorganisms whereas __________ have limited activity and are useful against a particular species

Answer 3

Broad spectrum, Narrow spectrum

Question 4

When should treatment be started before collecting and culturing a sample?

Answer 4

when the infection is serious

Question 5

What are the two major tests used to determine Minimal inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC)?

Answer 5

• Disc Diffusion (MIC)

- Broth dilution (MIC and MBC)

Question 6

Which type of antibiotics usually have a very similar MIC and MBC?

Answer 6

Bactericidal

Question 7

Which type of antibiotics have much higher MBC than MIC?

Answer 7

Bacteristatic

Question 8

Prophylaxis treatment is to __________ whereas Definitive treatment is used when_________

Answer 8

Prevent, the pathogen is identified.

Question 9

ADME is used in reference to what the body does to a drug which is called what?

Answer 9

Pharmacokinetics (PK)

Question 10

The drugs affect on the body is called what?

Answer 10

Pharmacodynamics (PD)

Question 11

What are the two goals of the antimicrobial dose?

Answer 11

1-Achieve a bactericidal concentration at the site
2-Discourage emergence of resistant bacteria

*Should be overkill without causing toxicity in the host

Question 12

In which growth phase are bacteria most sensitive to antimicrobial intervention?

Answer 12

Log or exponential phase

Question 13

Bactericidal antibiotics ______ bacteria while bacteriostatic antibiotics ______ bacterial growth

Answer 13

kill, stop

Question 14

What three things best describe Pharmacodynamic properties of antibiotics?

Answer 14

1-Concentration-dependence
2-Time dependence (rate of killing)
3-Time dependent with persistent effects

Question 15

The suppression of bacterial growth following antibiotic exposure is called what?

Answer 15

Persistent Post antibiotic effect (PAE)

Question 16

What are the 5 key rules for treating a serious infection?

Answer 16

1-Begin treatment ASAP (should still culture)
2-Use safest effective drug
3-Use the largest reasonable does
4-Monitor plasma concentration to guide dose/avoid toxicity
5-Continue treatment at least 2 days past “cure” (6-8 wk for CNS, 8-10 wk malaria, 6-12 months TB)

Question 17

What distinguishes antimicrobials from disinfectants?

Answer 17

selective toxicity (High selectivity = reduced adverse effects. Though some can still have side effects)

Question 18

The ratio of the dose toxic to the host to the effective therapeutic dose is known as?

Answer 18

Therapeutic index (higher the TI the safe the antibiotic)

Question 19

An effect on human cells resulting from the same mechanism as the anitmicrobial effect of an AMT is referred to as?

Answer 19

Analogous adverse effects

Question 20

Iriitation, allergies or other adverse reactions to an AMT is referred to as?

Answer 20

Independent adverse effect

Question 21

What does ADME stand for?

Answer 21

Absorption
Distribution
Metabolism
Excretion

Question 22

What are 4 inhibitory examples of antimicrobial target mechanisms?

Answer 22

1-Cell wall
2-Protein synthesis (50s and 30s subunit)
3-Metabolic pathways
4-Nucleic acid synthesis

Question 23

Why would you use a combination therapy? (5 reasons)

Answer 23

1-mixed infection
2-Improve efficacy
3-uncharacterized serious infection
4-lower drug concentrations
5-delay resistance

Question 24

Disruption of the micro biome by overuse or poor use of antimicrobial agents can lead to what?

Answer 24

Superinfections