Antibacterials 1

Question 1

bacteriostatic drug definition

Answer 1

causes reversible inhibition of growth (does not kill it) and relies on the host immune system to clear the bacteria

Question 2

the more selectively toxic the less ___________

Answer 2

adverse effects; selective of the invasive microorganisms

Question 3

what is the post antibiotic effect and some explanations for this?

Answer 3

when the killing action continues even when the dug plasma levels are near 0

• lag time for the bacterial to synthesize new enzymes
• persistence of agent
• enhanced susceptibility of bacteria

Question 4

________ helps classify bacteria as: susceptible, intermediate, or resistant

Answer 4

MIC (minimum inhibitory concentration)/ Minimum effective dose

Question 5

define MIC (minimum inhibitory concentration)

Answer 5

minimum concentration require to prevent visible bacterial growth

Question 6

MBC is typically slightly/much higher/lower than MIC for a bactericidal antibiotic

Answer 6

slightly higher

Question 7

MBC is typically slightly/much higher/lower than MIC for a bacteriostatic agent

Answer 7

much higher

Question 8

what are the different mechanism of action of antibacterials?

Answer 8

• disruption of DNA
• RNA polymerase inhibitors
• DNA gyrase inhibitors
• Folic acid synthesis inhibitors
• Cell wall synthesis inhibitors
• protein synthesis inhibitors

Question 9

when is gram staining bacterial useful?

Answer 9

for identifying presence and morphologic features of the organism in sterile body fluids such as CSF, pleural fluid, urine, etc

Question 10

what is empiric therapy and what influences the choice of drug

Answer 10

when immediate therapy is required

• site of infection
• patients history