Penicillins

Question 1

Give examples and spectrum of activity: natural penicillins,

Answer 1

Parenteral agents: Aqueous penicillin G (IV), Benzathine penicillin G (IM, long-acting), Procaine penicillin G (IM)
Oral agent: Penicillin VK

Gram-positives:
Group streptococci		
viridans streptococci	
Enterococcus spp.	
Bacillus spp.	 

Gram-Negative:
Neisseria spp.

Other
Treponema pallidum (syphilis) 

Anaerobes:
Clostridium not diff

Question 2

Give examples and spectrum of activity: the penicillinase‐resistant penicillins,

Answer 2

Nafcillin, Oxacillin, Dicloxacillin

MSSA

Question 3

Give examples and spectrum of activity: the aminopenicillins,

Answer 3

Amoxicillin (oral), Ampicillin

Gram-Positive:
Enterococcus spp.
Listeria monocytogenes

Gram-Negative:
Proteus mirabilis
some E. Coli
Salmonella, Shigella
Sensitive H. flu

Question 4

Give examples and spectrum of activity: the carboxypenicillins,

Answer 4

Ticarcillin (IV)

Enterobacter
Pseudomonas aeruginosa

Question 5

Give examples and spectrum of activity: the ureidopenicillins

Answer 5

Pipercillin (given with tazobactam)

Gram-Negative:
Enterobacter
Serratia
Klebsiella (some)
Pseudomonas aeruginosa

Anaerobics:
Fairly good

Question 6

Give examples and spectrum of activity: and the b‐lactamase inhibitor combinations

Answer 6

Parenteral agents: Ampicillin-sulbactam (Unasyn), Ticarcillin-clavulanate (Timentin®; not available), Piperacillin-tazobactam (Zosyn),
Oral agent: Amoxicillin-clavulanate (Augmentin)

Gram-Positive:
Staph aureus (not MRSA)

Gram-Negative:
Moraxella Catarrhalis
H flu

Anaerobic:
Bacteroides

Question 7

Which specific penicillin agents have activity against Staphylococcus aureus?

Answer 7

MSSA: Nafcillin, Oxacillin, Dicloxacillin; Ampicillin-sulbactam, ticarcillin-clavulanate, piperacillin-tazobactam; Oral agent: Amoxicillin-clavulanate

MRSA: NONE!

Question 8

,Which specific penicillin agents have activity against Pseudomonas aeruginosa

Answer 8

Piperacillin + tazobactam

Ticarcillin

Question 9

Which specific penicillin agents have activity against Bacteroides fragilis

Answer 9

MSSA: Nafcillin, Oxacillin, Dicloxacillin; Ampicillin-sulbactam, ticarcillin-clavulanate, piperacillin-tazobactam; Oral agent: Amoxicillin-clavulanate

Question 10

Mechanism of action: penicillins?

Answer 10

Bind PBPs, stop peptidoglycan from assembling, kill cell

Question 11

Time-dependent or concentration dependent?

Answer 11

Time-dependent