Antimicrobial Pharmacology - Classes Flashcards
Which antibiotics are active against the cell wall?
1) Beta-lactams
2) Vancomycin
3) Daptomycin
4) Fosfomycin
What is the mechanism of action of beta-lactams?
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.
What are the commercially-available natural penicillins?
1) Penicillin G
2) Penicillin V
What organisms are covered by the natural penicillins (penicillin G, penicillin V)
Excellent Coverage:
1) Streptococcus spp. (some resistance developing)
2) N. meningitidis
3) Oral anaerobes
4) Treponema pallidum (syphilis)
What organisms are not covered by natural penicillins (penicillin G, penicillin V)?
1) Staphylococcus spp.
2) Gram negative organisms
3) Gut anaerobes
Are natural penicillins (penicillin G, penicillin V) dose adjusted for renal impairment
Yes
What is one unique PK considerations for penicillin V?
1) Penicillin V is absorbed best on an empty stomach
What are common uses for the natural penicillins (penicillin G, penicillin V)
1) N. meningitidis meningitis
2) Syphilis
3) Some dental infections
What are the commercially-available aminopenicillins?
1) Amoxicillin
2) Ampicillin
What organisms are covered by the aminopenicillins (amoxicillin, ampicillin)
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)
What organisms are not covered by the aminopenicillins (amoxicillin, ampicillin)
1) Staphylococcus spp.
2) Tougher Gram negative organisms (e.g. Klebsiella spp.)
3) Gut anaerobes
Are aminopenicillins (amoxicillin, ampicillin) dose adjusted for renal impairment?
Yes
What is amoxicillin preferred over ampicillin?
1) Ampicillin needs to be taken on a empty stomach
2) Ampicillin causes more diarrhea than amoxicillin
What is one unique PK consideration for the natural penicillins?
1) Penicillin penetrates the CNS well if there is an inflamed meninges
What are common uses for the aminopenicillins (amoxicillin, ampicillin)?
1) Upper respiratory tract infections
2) Some dental infections
3) Known susceptible organisms
What are the commercially-available ureidopenicillins?
1) Piperacillin
2) Ticarcillin
What other names are ureidopenicillins known by?
1) Antipseudomonal penicillins
2) Extended-spectrum penicillins
How does cephalosporin spectrum of activity change with newer generations?
Increased Gram negative coverage.
In general, what organism will not be covered by cephalosporins?
1) MRSA
2) Enterococcus spp.
3) Listeria
How well do cephalosporins work against beta-lactamase inhibitors?
Works against most beta-lactamase producing organisms except for ESBL and ampC-producing organisms
What are the commercially available first generation cephalosporins?
1) Cefazolin
2) Cephalexin
3) Cefadroxil
What organisms are covered by the first generation cephalosporins (cefazolin, cephalexin, cefadroxil)?
Excellent
1) MSSA
2) Streptococcus spp.
Good
1) E. coli
2) Proteus mirabilis
3) Klebsiella spp.
4) Oral anaerobes
What organisms are NOT covered by the first generation cephalosporins (cefazolin, cephalexin, cefadroxil)?
1) MRSA
2) Enterococcus spp.
3) Listeria
4) Haemophilus influenzae
5) GI anaerobes
6) Other Gram negatives
What are common uses for the first generation cephalosporins (cefazolin, cephalexin, cefadroxil)?
1) Surgical prophylaxis
2) Streptococcus infections
3) Staphylococcus infections
4) UTIs (if documented susceptibility)
What are two PK considerations for first generation cephalosporins
1) Do not enter into the CNS
2) Must be renally adjusted in CKD/AKI
What are the commercially available second generation cephalosporins?
1) Cefprozil
2) Cefuroxime
3) Cefoxitin
FYI: Ceflacor was discontinued in 2014/2015
What organisms are covered by second generation cephalosporins (cefprozil, cefuroxime, cefoxitin)?
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)
What are common uses for the second generation cephalosporins (cefprozil, cefuroxime, cefoxitin)?
1) RTIs
2) CAP
3) Cefuroxime: Lyme disease
4) Cefoxitin: Surgical prophylaxis for intra-abdominal procedures
5) Cefoxitin: Mixed infection with anaerobes/aerobes
What are the commercially available third generation cephalosporins?
1) Cefixime
2) Ceftazidime
3) Cefotaxime
4) Ceftriaxone
What organisms are covered by third generation cephalosporins (cefixime, ceftazidime, cefotaxime, ceftriaxone)?
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
What is one unique PK consideration for third generation cephalosporins (cefixime, ceftazidime, cefotaxime, ceftriaxone)?
1) Best CNS penetration of cephalosporins
