Penicillin Flashcards
PBP 1a, 1b
Cell Elongation
- Inhibition causes cell lysis
PBP 2
Determines Bacteria Shape
- Inhibition causes formation of round forms which then lyse
PBP 3
Cell Division
- Inhibition: Continue to grow and eventually die
Resistance to Beta-Lactams
- Mechanisms
Beta-Lactamases
Reduced Affinity for Beta-Lactams
Impermeable Cell Membrane
Efflux
Penicillin Resistance
- Mechanisms
Beta-Lactamase
Changes in PBPs to have less affinity for Beta-Lactams
Penicillin Resistance
- Intrinsic Resistance
Enterobacterales
- Altered PBP
- Beta-Lactamases
- Cell Walls
Cloxacillin
- Use
Limited spectrum
- Better for bacterias with beta-lactamases
Aminopenicillin
- Use
- Increased PBP affinity
- Better entry into bacteria
- Good for Gram-Negatives
Ampicillin vs Amoxicillin
Ampicillin
- More diarrhea
- More skin rash
Clavulanic Acid
- Use
Inhibits beta lactamase
- Combine with amoxicillin
Piperacillin-Tazobactam
- No Improvement in what kind of organisms
AMP-C producing SPICE-A Organisms
S: Serratia
P: Providencia
I: Indole-Positive Proteus
C: Citrobacter
E: Enterobacter
A: Acinetobacter
Penicillins
- Metabolism/Excretion
Minor degree of metabolism
Most is excreted through urine by kidneys
Which Penicillins are affected by food
Penicillin G
Cloxacillin
Ampicillin
Which Penicillin does not need dose adjustment even when Cr/Cl < 10 mL/min
Cloxacillin
Interstitial Nephritis
- Symptoms
- What Type of Reaction
Type III Reaction
- Inflammation around kidneys
- Fever, Rash, Hematuria, Proteinuria
Neutropenia
- Symptoms
- What Type of Reaction
Type II Reaction
- Low neutrophil count
- WBC count returns back to normal after stopping penicillin
Coombs Positive Hemolytic Anemia
- Symptoms
- What Type of Reaction
Type II Reaction
- Penicillin binds to and destroys RBC
Drug Interactions
Allopurinol and Ampicillin
- Increased chances of Rash
Oral Contraceptives
Aminoglycosides
- In Vitro inactivation of both antibiotics
Probenecid
- Reduced excretion
- Increased levels
Ceftriaxone
- Adverse Effects
Biliary Sludge
Cefepime
- Adverse Effects
Neurotoxicity
Cefaclor
- Adverse Effects
Serum Sickness in Children
Which Cephalosporin is most likely to cause diarrhea
Cefuroxime and Cefixime
