Cell Wall Synthesis Inhibitors

Question 1

What makes antibiotic agents effective?

Answer 1

selective toxicity - acts on microbial components that aren’t in human cells

Question 2

When are antibiotics most effective?

Answer 2

During exponential growth phase (they inhibit parts of the microbes that are active during replication)

Question 3

Postantibiotic effec

Answer 3

PAE - antibiotic keeps inhibiting microbe after drug levels are redced in the serum, higher in intraceullur bacteriostatic agents because they stick around longer

Question 4

MIC

Answer 4

minimal inhibitory concentration, antibiotic in blood should exceed MIC by 2-8X

Question 5

what class of drugs are considered bacteriostatic?

Answer 5

protease inhibitors and folate synthesis inhibitors

Question 6

What drugs have lowest risk of superinfections? narrow spectrum, extended spectrum, or broad spectrum? Which have highest risk?

Answer 6

Narrow, Broad have highest risk of superinfections

Question 7

Which class contains more bacteriocidal drus?narrow spectrum, extended, or broad?

Answer 7

narrow and extended. Broad are almost all bacteriostatic.

Question 8

A drugs clinical effectiveness is reliant on A) maximal efficacy, or B) maximal potency?

Answer 8

A) maximal efficacy

Question 9

What is the chemotherapeutic index?

Answer 9

a measure of the safety of a drug. The difference between TD50 and ED50. Larger the ratio, the

Question 10

What is the main way antimicrobial drugs become resistant?

Answer 10

Acquired microbial resistance - drug fails to reach target, drug is inactivated, or drug target is altered.

Question 11

How is drug resistance acquired?

Answer 11

transduction (bacteriophages, important in staphylococcal spp) and Conjugation (mating organisms like gram negative)

Question 12

What do strep pneumonia, MRSA, and VRE have in common?

Answer 12

all have resistance that is important in hospital stays

Question 13

why do you not use bacteriocidal and bacteriostatic drugs?

Answer 13

They have an antagonistic effect. Bacteriocidal drugs need the virus to be replicating and static drugs inhibit replication

Question 14

Two bacteriostatic drugs that become bacteriocidal together. what is a term to describe this?

Answer 14

Synergism- by blocking sequential steps of a pathway, inhibition of drug-inactivating enzyme, and enhancement of drug uptake

Question 15

What is metronidazole used for?

Answer 15

Targets anaerobes, the gold standard for surgical prophylaxis antibiotics.
-50% of antibiotics are administered for prophylaxis

Question 16

All of the following are adverse effects of antimicrobial therapy, which one is most important to Qualle?

Answer 16

Allery, Super infections, Organ Toxicity, and selection of resistant microorganisms

Selection of resistant microorganisms

Question 17

Which statement concerning antimicrobial therapy is false?
A. synergism can be achieved by combining two bacteriostatic antibiotics
B. super infections arise during treatment of a primary infection due to outgrowth of resistant microorganisms
C. Combination antimicrobial therapy is called for in the treatment of polymicrobial infections
D. Drug resistance is avoided by combination antimicrobial therapy
E. some bacteria express drug-inactivating enzymes that cause antimicrobial drug resistance

Answer 17

D. Using combination drugs actually increases drug resistance.