Antibacterials: Summaries Flashcards
Inhibitors of cell wall synthesis:
Antibacterials
Resistance
Other
Beta-lactams (penicillins, cephalosporins, monobactams, carbapenems)
Vancomycin
Fosfomycin
Gram+: PBP affinity
Gram-: efflux, porins, beta-lactamases
Vanco: target site & thickened cell wall
B: most commonly used antibiotics
V: gram+ if IV, C. difficile if orally
F: urinary tract infections
Inhibitors protein synthesis:
Antibacterials
Resistance
Aminoglycosides Macrolides Tetracyclines, Tigecycline Clinamycin Linezolid
Target site
Efflux pumps
Enzymatic modification
Inhibitors DNA/RNA synthesis:
Antibacterials
Resistance
Other
TMP/SMX
Rifamycins (rifampin)
Fluoroquinolones
Fidamoxicin
All: target site
FQ: efflux & enzymatic modification
R: red/orange discoloration, drug-drug interactions
FQ: Moxifloxacin
F: C. difficile
DNA damaging agents:
Antibacterials
Other
Nitrofurantoin
Metronidazole
N: urinary tract infections, causes pulmonary fibrosis
M: anaerobes, C. difficile
Cell membrane damaging agents:
Antibacterials
Resistance
Daptomycin
Polymyxins
Complex or still in process
Concentration Dependent Drugs (4)
Aminoglycosides
Quinolones
Daptomycin
Metronidazole
Time Dependent Drugs (3)
Beta-lactams
Linezolid
TMP/SMX
Exposure Dependent Drugs (6)
Vancomycin Polymyxins Tigecycline Tetracyclines Macrolides Clindamycin
One-Sided Antibiotics:
Gram+ (7)
Vancomycin (when given IV)
Daptomycin
Linezolid
Rifampin
Oxa-/Naf-/Dicloxa-cillin (penicillinase-resistant penicillins, good for strep & esp staph)
Fidaxomicin
Penicillin
One-Sided Antibiotics:
Gram- (4)
Polymyxins
Ceftazidime (only 3rd generation ceph w/ activity for pseudomonas, much better for – than +)
Ciprofloxacin (FQ not great for strep, whereas Levo & Moxi were much better)
Aztreonam (only monobactam, doesn’t have cross-reactivity for pts w/ penicillin allergies)
One-Sided Antibiotics:
Gram+ & Anaerobes (1)
Gram- & Gram+ Synergy (1)
Anaerobes & C. difficile
Clindamycin
Aminoglycoside
Metronidazole
Gram+ Bacteria:
Cell Wall
Important Bugs (3)
Thick, made of peptidoglycan
- Streptococcus spp. (S. penumoniae)
- Staphylococcus spp. (S. aureus)
- Enterococcus spp. (E. faecalis, E. faecium)
Gram- Bacteria:
Cell Wall
Important Bugs (5)
Thin, protected by an outer cell membrane
- Haemophilus influenzae
- Proteus mirabilis
- Enterobacteriaceae (Escherichia coli, Klebsiella pneumonia, Enterobacter spp.)
- Pseudomonas aeruginosa
- Acinetobacter spp.
Anaerobic Bacteria:
Properties (3)
Important Bugs (4)
- Grow in absence of oxygen
- Some pathogenic, others less
- Can be gram+ or gram-
- Bacteroides fragilis (most problematic, lives in gut)
- Clostridium spp.
- Peptostreptococcus
- Propionibacterium
Atypical Bacteria:
Properties (3)
Important Bugs (4)
- Community > Hospital acquired
- Lack a cell wall, can’t gram stain
- Drugs that inhibit cell wall synth will be inactive against atypicals
- Chlamydia spp.
- Legionella pneumonia
- Mycoplasma pneumonia
- Rickettsia reckettssii
Drugs Against Pseudomonas Aeruginosa
P. aeruginosa: gram-
For P-Ts, Carb not Erta & FQ not Moxi TACC PA
Piperacillin/tazobactam Carbapenems (not Erta) Fluoroquinolones (not Moxi) Ticarcillin-clavulanate Aztreonam Cefepime Ceftazidime Polymyxins Aminoglycosides
Drugs Against Methicillin-Resistant S. aureus (MRSA)
MRSA: gram+
Drugs To Confidently Treat Very Lethal Commensals
Daptomycin TMP/SMX Ceftaroline Tetracyclines/Tigecycline Vancomycin Linezolid Clindamycin
Drugs Against Vancomycin-Resistant Enterococcus (VRE)
VRE: gram+
Learn VRE Drugs for Test
Linezolid
Daptomycin
Tigecycline
Drugs Against Anaerobes
Antibiotics covering Bacteroides typically have broad-spectrum anaerobic activity
These Many Meds Can Confidently Cover Bacteroides
Tigecycline Moxifloxacin Metronidazole Cefoxitin Clindamycin Carbapenems Beta-lactam + Beta-lactamase Inhibitors
Drugs Against Atypicals
No cell wall: Legionella, Mycoplasma pneumoniae, Chlamydia pneumoniae
Three Fair Meds
Tetracyclines
Fluoroquinolones
Macrolides
Summary of Spectrum of Activity of Cephalosporins:
1st –> 2nd –> 3rd generation
None cover…
Cefoxitin
Ceftaroline
Cefepime
Go from more G+ to more G-
Enterococcus
Covers Bacteroides & MSSA (poorly)
ONLY beta-‐lactam w/ MRSA coverage
4th generation, has broadest spectrum
Key Toxicities:
Nephrotoxicity (3)
Aminoglycosides
Polymyxins
Vancomycin
Key Toxicities: Clostridium difficile (2)
Clindamycin
Fluoroquinolones
Key Toxicities:
Seizures / CNS (2)
Imipenem
Fluoroquinolones
