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Flashcards in Antibacterials: Summaries Deck (33):
1

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

2

Inhibitors protein synthesis:

Antibacterials

Resistance

Aminoglycosides
Macrolides
Tetracyclines, Tigecycline
Clinamycin
Linezolid

Target site
Efflux pumps
Enzymatic modification

3

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

4

DNA damaging agents:

Antibacterials

Other

Nitrofurantoin
Metronidazole

N: urinary tract infections, causes pulmonary fibrosis
M: anaerobes, C. difficile

5

Cell membrane damaging agents:

Antibacterials

Resistance

Daptomycin
Polymyxins

Complex or still in process

6

Concentration Dependent Drugs (4)

Aminoglycosides
Quinolones
Daptomycin
Metronidazole

7

Time Dependent Drugs (3)

Beta-lactams
Linezolid
TMP/SMX

8

Exposure Dependent Drugs (6)

Vancomycin
Polymyxins
Tigecycline
Tetracyclines
Macrolides
Clindamycin

9

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

10

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)

11

One-Sided Antibiotics:

Gram+ & Anaerobes (1)

Gram- & Gram+ Synergy (1)

Anaerobes & C. difficile

Clindamycin

Aminoglycoside

Metronidazole

12

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)

13

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.

14

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

15

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

16

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

17

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

18

Drugs Against Vancomycin-Resistant Enterococcus (VRE)

VRE: gram+

Learn VRE Drugs for Test

Linezolid
Daptomycin
Tigecycline

19

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

20

Drugs Against Atypicals

No cell wall: Legionella, Mycoplasma pneumoniae, Chlamydia pneumoniae

Three Fair Meds

Tetracyclines
Fluoroquinolones
Macrolides

21

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

22

Key Toxicities:
Nephrotoxicity (3)

Aminoglycosides
Polymyxins
Vancomycin

23

Key Toxicities:
Clostridium difficile (2)

Clindamycin
Fluoroquinolones

24

Key Toxicities:
Seizures / CNS (2)

Imipenem
Fluoroquinolones

25

Key Toxicities:
Myopathy (1)

Daptomycin

26

Key Toxicities:
Rash (3)

TMP/SMX
Beta-lactams
Vancomycin (Red Man's)

27

Key Toxicities:
Pulmonary Fibrosis (1)

Nitrofurantoin

28

Key Toxicities:
Myelosuppression (1)

Linezolid

29

Key Pharmacokinetics:
Fe/Ca/Mag/Al & Bioavailability (2)

Fluoroquinolones
Tetracyclines

30

Key Pharmacokinetics:
Beta-lactam, but NO renal adjustments (2)

Ceftriaxone
Penicillinase-resistant PCNs

31

Key Pharmacokinetics:
FQ, but NO renal adjustment (1)

Moxifloxacin

32

Key Pharmacokinetics:
Commonly used agents for CNS infections (moderate penetration) (3)

3rd/4th generation Cephalosporins
Meropenem
Vancomycin

33

Key Pharmacokinetics:
Low Vd (not useful for CNS) (4)

Aminoglycosides
Polymyxins
Daptomycin
Nitrofurantoin