Question 1

Which of the following best describes the general goal of antimicrobial drug action?

Accepted Answer

To interfere with the metabolism or structure of a microorganism so it cannot survive or reproduce

Question 2

A drug that kills microorganisms is referred to as:

Accepted Answer

Microbiocidal

Question 3

Which mechanism of antimicrobial action is most likely to cause cell lysis in bacteria, as illustrated by the bursting balloon image?

Accepted Answer

Inhibition of cell wall synthesis

Question 4

Penicillin and cephalosporins primarily target which bacterial structure?

Accepted Answer

Cell wall

Question 5

Why are drugs that inhibit protein synthesis generally less toxic to humans?

Accepted Answer

Bacterial ribosomes are structurally different from human ribosomes

Question 6

Which antimicrobial mechanism involves mimicking the normal substrate of an enzyme to block its activity?

Accepted Answer

Competitive inhibition

Question 7

Broad spectrum antibiotics are more likely to cause which complication?

Accepted Answer

Superinfection due to destruction of normal flora

Question 8

Which equation best represents the therapeutic index (TI) of a drug?

Accepted Answer

$$TI = \frac{LD_{50}}{ED_{50}}$$

Question 9

A patient develops antibiotic-associated colitis after taking broad spectrum antibiotics. Which organism is most likely responsible?

Accepted Answer

Clostridioides difficile (C. diff)

Question 10

Which method is used to determine the minimal inhibitory concentration (MIC) of an antibiotic?

Accepted Answer

Dilution method

Question 11

What is the main advantage of using a narrow spectrum antibiotic?

Accepted Answer

It targets a specific group of pathogens, reducing risk of superinfection

Question 12

Which of the following is NOT a factor to consider when selecting an antimicrobial drug?

Accepted Answer

Ability to stimulate antibody production

Question 13

Which mechanism of resistance involves bacteria pumping out antibiotics to reduce their intracellular concentration?

Accepted Answer

Increased drug elimination

Question 14

A patient is prescribed metronidazole for Giardia infection. Which side effect should they be warned about?

Accepted Answer

Black hairy tongue

Question 15

Which of the following is a semisynthetic antibiotic?

Accepted Answer

Ampicillin

Question 16

Which of the following is a recommended strategy to prevent the development of drug resistance?

Accepted Answer

Use antibiotics with a narrow target when possible

Question 17

Which antihelminthic drug is contraindicated in pregnant women due to its effect on fetal development?

Accepted Answer

Mebendazole

Question 18

Which of the following is a plausible reason why antiviral drugs are difficult to develop?

Accepted Answer

Viruses lack metabolic pathways distinct from host cells

Question 19

Which of the following is a plausible outcome of combining two drugs that are individually non-toxic?

Accepted Answer

The combination may cause toxic effects not seen independently

Question 20

Which of the following best describes selective toxicity?

Accepted Answer

The drug kills harmful microorganisms without damaging the host

Chapter 11

Study Guide - Practice Questions