Antibiotics

Question 1

What are antibiotics that are only effective against a small number of bacteria?

Answer 1

Narrow Spectrum

Question 2

What are antibiotics that are effective against many bacteria called?

Answer 2

Broad spectrum

Question 3

What antibiotic has the widest spectrum of kill?

Answer 3

Tetracycline

Question 4

What’s the difference between bactericidal and bacteriostatic?

Answer 4

Bactericidal - kills bacteria, Bacteriostatic - inhibits bacterial growth

Question 5

Never combine a ___________ antibiotic with a ___________ antibiotic in the same person because?

Answer 5

Bacericidal, Bacteriostatic - because bacteriostatics will inhibit the effects of bactericidal antibiotic

Question 6

All antibiotics are _________, but not all antibiotics are ___________ at therapeutic doses?

Answer 6

Bacteriostatic, Bactericidal

Question 7

What is minimum inhibitory concentration, and what is it used for?

Answer 7

• Used to determine bactericidal concentration of an antibiotic
• Antibiotics added to test tubes, concentration is the one that kill 100% of the bacteria

Question 8

Do we give humans antibiotics that reach MIC?

Answer 8

No, it may kill the person - we give less of the antibiotic to get bacteriostatic effect

Question 9

What is antibiotic synergism?

Answer 9

When 2 antibiotics work together for a more positive effect when given to the same patient

Question 10

Give an example with antibiotic synergism.

Answer 10

Enterococci infection treated with penicillin and streptomycin to completely kill

Question 11

What is the predominant microorganism in the oral cavity?

Answer 11

Gram positive strep or staph

Question 12

What do all oral/facial infection occur from?

Answer 12

Resident microorganisms which are already in the mouth

Question 13

Why is penicillin always the drug of choice for orofacial infections?

Answer 13

It is the most effective antibiotic against gram postive strep or staph

Question 14

What is the least toxic antibiotic?

Answer 14

penicillin - cannot kill the host at any concentration

Question 15

What is penicillin considered to be; bactericidal or bacteriostatic?

Answer 15

Bactericidal

Question 16

What are the 4 ways to minimize resistance?

Answer 16

1. Adequate dose
2. Adequate duration
3. Avoid repeated administration
4. Avoid topical administration

Question 17

How do you choose an antibiotic?

Answer 17

1. Identify microorganism
2. Determine most effective antibiotic against organism
3. Choose an antibiotic with low host toxicity
4. Choose a bactericidal antibiotic
5. Choose an antibiotic with low resistance potential

Question 18

Is it safer to give a lower dose to avoid anaphylactic shock?

Answer 18

No - allergic reactions are not dose-dependent

Question 19

What happens in microbial resistance?

Answer 19

Bacteria resists drug therapy - making drug ineffective

Question 20

What does nosocomial infection mean?

Answer 20

Hospital-acquired infection

Question 21

How do pathogens and tumor cells show microbial resistance?

Answer 21

• Developed mechanisms to inactivate drugs before they bind to targets
• Mutations to prevent the uptake of the drug
• Ability to cause **active drug efflux from the cell **- pushed drug out of cell

Question 22

What are sulfa drugs primarily used for?

Answer 22

Urinary tract infections (UTI’s)

Question 23

What was the first antibacterial agent?

Answer 23

Sulfanilamide

Question 24

What is Trimethoprim?

Answer 24

A sulfa drug used for UTI - brand name = Bactrim