7.5 Intro to Antimicrobials

Question 1

What is selective toxicity?

Answer 1

• Microbes can have structures and or processes that human cells do not have.
• Anti-mictobial “selective toxicity” refers to the ability of these drugs to kill or inhibit the growth of microbes, leaving the human host unharmed.

Question 2

What is pharmacodynamic bactericidal principles used for?

Answer 2

-Used for antibacterial dosage regimen design

Question 3

What is a concentration dependent killer?

Answer 3

Peak/MIC best activity when the peak drug level exceeds the MIC by a certain magnitude.

Question 4

What is a time dependent killer?

Answer 4

Time is greater than MIC, best activity when the drug level stays above MIC

Question 5

Explain the post antibiotic effect?

Answer 5

Both time dependent killer and concentration dependent killer can include post antibiotic effect when bacterial growth is inhibited for a time after the drug levels drop below the MIC of the organism

Question 6

How can the post antibiotic affect antibacterial dosing?

Answer 6

Can allow for a longer interval between drug doses

Question 7

What is Antibiotic Effectiveness?

Answer 7

1) Must reach its target in an active form
2) Bind to the target
3) Interfere with its function

Question 8

What are mechanisms of Antibiotic Resistance?

Answer 8

1) The drug does not reach its target
2) the drug is inactivated
3) The target or biochemical pathways is altered so drug cannot bin and or act
4) Altered target site decreased up take, decreased penetration, increased efflux, enzymatic inactivation or modification, and bypass pathways.

Question 9

What are some antibiotic resistance concerns?

Answer 9

1) some bacteria are able to survive every modern antibiotic.
2) Antimicrobial resistance is a problem so serious that it threatens the achievements of modern medicine. A post antibiotic era is which common infections and minor injuries can kill- far from being an apocalyptic fantasy is instead a very real possibility for the 21st century.

Question 10

Where does research show antimicrobial resistance is stemming from?

Answer 10

It may be coming from antibiotics used in agriculture.

Question 11

What are some ways to improve antibiotic utilization?

Answer 11

1) Formulary restriction and preauthorization.
2) Prospective audit with intervention and feedback.
3) Standardized order sets and clinical pathways (Foster evidence based prescribing.
4) Antimicrobial order forms
5) De-escalation of therapy (review culture and sensitive results)
6) Dose optimization
7) Intravenous to oral dose conversion

Question 12

What is MIC?

Answer 12

Minimum inhibitory concentration

Question 13

What is De-escalation of antimicrobial therapy?

Answer 13

• Review culture and sensitivity (C&S) results; on going review of therapy.
• Discontinue antimicrobials
• Switch to more focused therapy based on culture/sensitivity results
• Change to oral antimicrobials

Question 14

What is an antibiogram?

Answer 14

It is a local summary of selected antibiotic activity versus common bacterial isolates; it is used for drug formulary decision and to guide empiric treatment.

Question 15

In the culture and sensitivity reports what does S, R, and I stand for?

Answer 15

S=sensitive
R= Resistant
I=Intermediate.