Abx 2 (inhibitors of cell wall synthesis) Flashcards
1
Q
Penicillin G (Benzathine)
A
- Beta Lactam
- Standard narrow spectrum
- G+
- Parenteral
- DOC for syphilis
- Repository prep- 1 IM dose producing persistent but low blood levels
2
Q
Penicillin V
A
- Beta Lactam
- Standard narrow spectrum
- G+
- PO
- DOC for syphilis
3
Q
Nafcillin
A
- Beta Lactam
- Penicillin resistant narrow spectrum
- Used against Pen G resistant staphylococcal (MSSA)
4
Q
Amoxicillin
A
- Beta Lactam
- Aminopenicillins broad spectrum
- G+
- G- due to increased penetration through porins
- Orally often with B-lactamase inhibitors
5
Q
Ticarcillin
A
- Beta Lactam
- Antipseudomonal extended spectrum
- Spectrum includes aminopenicillins PLUS Pseudomonas aeruinosa
- Used IV for serious hospital aquired G- infections
- Ticarcillin of large IV dose = Na+ overload = CHF
6
Q
Piperacillin
A
- Beta Lactam
- Antipseudomonal extended spectrum
- Spectrum includes aminopenicillins PLUS Pseudomonas aeruinosa
- Used IV for serious hospital aquired G- infections
7
Q
Clavulanic Acid
A
- Beta Lactam
- Fixed dose with B-lactamase inhibitors
- Amoxicillin/Clavulanate
- Ticarcillin/Clavulanate
- Restores spectrum of activity against B-lactamase producing bacteria (but not altered PBPs)
8
Q
Cefazolin
A
- 1st generation
- G+ MSSA (but not MRSA)
- Commonly used immediately before surgery
- Alternative to Penicillins when mild allergy exists
9
Q
Cefoxitin
A
- 2nd generation
- G- bacteria
- Largely replaced by 3rd generation
10
Q
Ceftriaxone
A
- 3rd generation
- G-
- Penetrates into CNS
- Tx meningitis and gonorrhea
11
Q
Cefepime
A
- 4th generation
- Good CNS penetration
- Empirical Tx of hospitalized pts when resistance due to extended spectrum B-lactamase
12
Q
Imipenem/Cilastatin
A
- Beta Lactam
- Broad spectrum
- Resistant to B-Lactamase except class A KPC and B NDM-1 carbapenemases
- Parenterally
- Fixed dose to prevent renal inactivation
- Tx for multi drug resisteant infections
- Risk of seizures with Imipenem
13
Q
Aztreonam
A
- Beta Lactam (but not fused with second ring)
- Narrow spectrum
- G- & Pseudomonas
- IV (poor oral absorption)
- Renal excretion
- Resistant to B-Lactamase (except KPC)
14
Q
Vancomycin
A
- Glycopeptide
- Reserved for serious infection
- Prevents polymerization of cell wall precursors (binds D-Ala-D-Ala terminus of the NAM monomer)
- Only G+ (too large for G-)
- VRE and VRSA due to D-Ala-D-lactate decreasing binding affinity
- IV (PO if GI infection)
15
Q
Fosfomycin
A
- Glycopeptide
- Phosphoenolpyruvate analogue
- Tx G- UTIs
- Inhibits production of murein monomers (blocks synthesis of UDP-NAM)
- Enters bacteria via glycerophosphate transporter (not found in host cells)
16
Q
Bacitracin
A
-Glycopeptide
-Inhibits bactoprenol dephosphorylation (carrier across inner membrane, must be dephos to return to carry another monomer)
-G+
-Acquired resistance uncommon
Available in topical fixed dose with neomycin/polymyxin (neosporin)
-Highly nephrotoxic is admin systemically
17
Q
Pharmokinetics of Beta Lactams
A
- Not orally well absorbed –> diarrhea
- Short half lives; given frequently
- Blocked by probenecid so concentrations high in urine
18
Q
Adverse reactions of Beta Lactams
A
- Least toxic of all Abx (pregnancy use ok)
- Jarisch-Herxheimer
- CNS toxicity with high doses
- Repository preps fatal if given IV (benzathine)
- Rashes not allergy related (Amoxicillin)
19
Q
Penicillin Allergy
A
- Can occur in absence of prior drug exposure (unknown exposure through moldy bread)
- Urticarial rash, fever, bronchospasm, SJS, anaphylaxis
- Immediate hypersensitivity (angioedema/anaphylaxis) may be fatal; Tx with Epi
20
Q
Cephalosporins Overall
A
From 1st to 5th generation:
- Increasing activity against G-/anaerobes
- Increasing resistance to B-Lactamase
- Increasing penetration into CNS
21
Q
Vancomycin Treatment Uses:
A
- Parenteral (MRSA)
- Combo with 3rd generation for meningitis
- PO for severe CDAD (used if metronidazole is ineffective)
- Severe G+ alternative to Penicillin
22
Q
Vancomycin Adverse Reactions:
A
- Ototoxic
- Nephrotoxic
- “red man syndrome” with rapid infusion due to histamine release
- Thrombophlebitis with IV (admin dilute slowly)