Antimicrobial Pharmacology - Classes

Question 1

Which antibiotics are active against the cell wall?

Answer 1

1) Beta-lactams
2) Vancomycin
3) Daptomycin
4) Fosfomycin

Question 2

What is the mechanism of action of beta-lactams?

Answer 2

1) Inhibits formation of the cell wall in bacteria by inhibiting the cross-linking of peptidoglycan chains.
2) Activates autolytic enzymes that destroy the cell wall.

Question 3

What are the commercially-available natural penicillins?

Answer 3

1) Penicillin G

2) Penicillin V

Question 4

What organisms are covered by the natural penicillins (penicillin G, penicillin V)

Answer 4

Excellent Coverage:

1) Streptococcus spp. (some resistance developing)
2) N. meningitidis
3) Oral anaerobes
4) Treponema pallidum (syphilis)

Question 5

What organisms are not covered by natural penicillins (penicillin G, penicillin V)?

Answer 5

1) Staphylococcus spp.
2) Gram negative organisms
3) Gut anaerobes

Question 6

Are natural penicillins (penicillin G, penicillin V) dose adjusted for renal impairment

Answer 6

Yes

Question 7

What is one unique PK considerations for penicillin V?

Answer 7

1) Penicillin V is absorbed best on an empty stomach

Question 8

What are common uses for the natural penicillins (penicillin G, penicillin V)

Answer 8

1) N. meningitidis meningitis
2) Syphilis
3) Some dental infections

Question 9

What are the commercially-available aminopenicillins?

Answer 9

1) Amoxicillin

2) Ampicillin

Question 10

What organisms are covered by the aminopenicillins (amoxicillin, ampicillin)

Answer 10

Excellent Coverage:

1) Enterococcus spp.
2) Listeria spp.
3) Helicobacter pylori
4) Oral anaerobes

Good Coverage:

1) Streptococcus spp.
2) Wimpy Gram negative organisms (e.g. E. coli, Proteus mirabilis, Salmonella spp., Shigella spp., Haemophilus influenzae)

Question 11

What organisms are not covered by the aminopenicillins (amoxicillin, ampicillin)

Answer 11

1) Staphylococcus spp.
2) Tougher Gram negative organisms (e.g. Klebsiella spp.)
3) Gut anaerobes

Question 12

Are aminopenicillins (amoxicillin, ampicillin) dose adjusted for renal impairment?

Answer 12

Yes

Question 13

What is amoxicillin preferred over ampicillin?

Answer 13

1) Ampicillin needs to be taken on a empty stomach

2) Ampicillin causes more diarrhea than amoxicillin

Question 14

What is one unique PK consideration for the natural penicillins?

Answer 14

1) Penicillin penetrates the CNS well if there is an inflamed meninges

Question 15

What are common uses for the aminopenicillins (amoxicillin, ampicillin)?

Answer 15

1) Upper respiratory tract infections
2) Some dental infections
3) Known susceptible organisms

Question 16

What are the commercially-available ureidopenicillins?

Answer 16

1) Piperacillin

2) Ticarcillin

Question 17

What other names are ureidopenicillins known by?

Answer 17

1) Antipseudomonal penicillins

2) Extended-spectrum penicillins

Question 18

How does cephalosporin spectrum of activity change with newer generations?

Answer 18

Increased Gram negative coverage.

Question 19

In general, what organism will not be covered by cephalosporins?

Answer 19

1) MRSA
2) Enterococcus spp.
3) Listeria

Question 20

How well do cephalosporins work against beta-lactamase inhibitors?

Answer 20

Works against most beta-lactamase producing organisms except for ESBL and ampC-producing organisms

Question 21

What are the commercially available first generation cephalosporins?

Answer 21

1) Cefazolin
2) Cephalexin
3) Cefadroxil

Question 22

What organisms are covered by the first generation cephalosporins (cefazolin, cephalexin, cefadroxil)?

Answer 22

Excellent

1) MSSA
2) Streptococcus spp.

Good

1) E. coli
2) Proteus mirabilis
3) Klebsiella spp.
4) Oral anaerobes

Question 23

What organisms are NOT covered by the first generation cephalosporins (cefazolin, cephalexin, cefadroxil)?

Answer 23

1) MRSA
2) Enterococcus spp.
3) Listeria
4) Haemophilus influenzae
5) GI anaerobes
6) Other Gram negatives

Question 24

What are common uses for the first generation cephalosporins (cefazolin, cephalexin, cefadroxil)?

Answer 24

1) Surgical prophylaxis
2) Streptococcus infections
3) Staphylococcus infections
4) UTIs (if documented susceptibility)

Question 25

What are two PK considerations for first generation cephalosporins

Answer 25

1) Do not enter into the CNS | 2) Must be renally adjusted in CKD/AKI

Question 26

What are the commercially available second generation cephalosporins?

Answer 26

1) Cefprozil 2) Cefuroxime 3) Cefoxitin FYI: Ceflacor was discontinued in 2014/2015

Question 27

What organisms are covered by second generation cephalosporins (cefprozil, cefuroxime, cefoxitin)?

Answer 27

1) Staphylococcus (less than first generation cephalosporins) 2) Streptococcus (better than first generation cephalosporins) 3) Improved Gram negative coverage compared to first generation cephalosporins (e.g. H. influenzae and Moraxella catarrhalis) 4) Cefoxition: Above coverage + anaerobes (but increasing resistance)

Question 28

What are common uses for the second generation cephalosporins (cefprozil, cefuroxime, cefoxitin)?

Answer 28

1) RTIs 2) CAP 3) Cefuroxime: Lyme disease 4) Cefoxitin: Surgical prophylaxis for intra-abdominal procedures 5) Cefoxitin: Mixed infection with anaerobes/aerobes

Question 29

What are the commercially available third generation cephalosporins?

Answer 29

1) Cefixime 2) Ceftazidime 3) Cefotaxime 4) Ceftriaxone

Question 30

What organisms are covered by third generation cephalosporins (cefixime, ceftazidime, cefotaxime, ceftriaxone)?

Answer 30

1) Streptococcus spp. (better than second generation cephalosporins, specifically cefotaxime and ceftriaxone) 2) Staphylococcus (less than second generation cephalosporins) 3) Improved Gram negative coverage compared to second generation cephalosporins (e.g. Neisseria spp.) 4) Ceftazidime: Covers Pseudomonas aeruginosa, but less Gram positive coverage than other third generation cephalosporins

Question 31

What is one unique PK consideration for third generation cephalosporins (cefixime, ceftazidime, cefotaxime, ceftriaxone)?

Answer 31

1) Best CNS penetration of cephalosporins