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Flashcards in Barbarians at the Wall Deck (33)
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1
Q

What type of bacteria do extended spectrum antibiotics affect?

A

Affect gram positive and SOME gram negative bacteria

2
Q

Bacteriostatic antibiotics work by…

A

Inhibiting a particular process, such as protein synthesis

3
Q

What is a con of bacteriostatic antibiotics?

A

They have no affect on particular mechanisms, thus can be overcome.

4
Q

How does a bacteriostatic antibiotic help to eliminate bacteria?

A

The immune system eliminates the drug once the antibiotic has suspended growth

5
Q

Why is bacteriocidal preferred? (4 reasons)

A
  1. Reduces number, so makes it easier for host to kill ALL bacteria
  2. More rapid
  3. Irreversibly damages bacteria
  4. Complete killing occurs (good for endocarditis or immunocompromised patients)
6
Q

What factors affect the choice of antibiotic? (3)

A
  1. specificity
  2. spectrum
  3. concentration of antibiotic at infection site
7
Q

What factors affect the antibiotic reaching the desired site? (6)

A
  1. pH
  2. movement of drug across mem
  3. presence of pus
  4. presence of hemoglobin
  5. anaerobic conditions
  6. presence of foreign body
8
Q

How does pus affect antibiotic administration?

A

Difficult for drug to penetrate pus

9
Q

How does hemoglobin affect antibiotic usage?

A

**

10
Q

How does a foreign body affect antibiotic usage?

A

**

11
Q

What are some “host factors” that must be considered when giving a patient antibiotics? (5)

A
Host defense mechanisms
Age
Renal/liver
Pregnancy/nursing
Blood perfusion
12
Q

What is the appropriate treatment for mixed bacterial infections?

A

Combination of effective agents

13
Q

What is the appropriate treatment for severe/unknown infections?

A

Use a broad spectrum to eliminate ANY pathogens

14
Q

How is the frequency of resistance to two drugs calculated?

A

Multiply individual frequencies of resistance.

15
Q

Toxicity at the primary site of drug excretion.

A

Nephrotoxicity

16
Q

Toxicity at the primary site of drug metabolism.

A

Hepatotoxicity

17
Q

Nephrotoxicity

A

Toxicity at the primary site of drug excretion.

18
Q

Hepatotoxicity

A

Toxicity at the primary site of drug metabolism.

19
Q

Possible result of treatment with an antibiotic, especially if it is broad spectrum?

A

Superinfections, especially due to alterations in normal GI flora (*Clostridium dificil)

20
Q

What is a possible result of poor adherence or subtherapeutic dosage of antibiotic?

A

Bacteria without resistance are selected against, and the surviving bacteria cannot be killed with antibiotic.

21
Q

Qualities of an ideal antibiotic. (5)

A
  1. bacteriocidal (preferably in 5-7 days)
  2. narrowest spectrum possible
  3. high tissue concentration (above minimal lethal concentration of abx)
  4. long half-life
  5. Nontoxic to animal cells
22
Q

How can you extend the expression of a particular drug?

A

Combining it with another antibiotic or other specific agents

23
Q

Bacteriostatic of Bactericidal: Erythromycin

A

Bacteriostatic

24
Q

Bacteriostatic of Bactericidal: Penicillin

A

Bactericidal

25
Q

Bacteriostatic of Bactericidal: Clindamycin

A

Bacteriostatic

26
Q

Bacteriostatic of Bactericidal: Polymixins

A

Bactericidal

27
Q

Bacteriostatic of Bactericidal: Vancomycin

A

Bactericidal

28
Q

Bacteriostatic of Bactericidal: Sulfa drugs

A

Bacteriostatic

29
Q

T/F: A possible goal of combination therapy is to use one of the antibiotics in smaller doses.

A

True

30
Q

What is intrinsic resistance?

A

Microbial resistance that was present prior to abx administration

31
Q

T/F: Antibiotics cause resistance.

A

F: “not necessarily”

32
Q

Common mechanisms of drug resistance:

A

1) decreased transport of drug across cell wall 2) increased efflux 3 )inactivation 4) alternative metabolic pathways 5) defect in metabolism/activation

33
Q

What are some common misuses of antibiotics?

A

Treatment of “insensitive” infections (viral); Treatment of fever of undetermined origin; Wrong/No diagnosis of organism