Intro to Antimicrobial Therapy Part 2 Flashcards Preview

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Flashcards in Intro to Antimicrobial Therapy Part 2 Deck (23):
1

Three primary schemes are used for classification of antimicrobial drugs. WHat are they?

1. Classification by Susceptible Organism
2. Classification by Mechanism of Action
3. Classification on whether drugs inhibit bacterial growth or are lethal to bacterial cells

2

What are the classifications of susceptible organisms?
5

Antibacterial Drugs—active against bacteria

Antifungals —active against fungi
Antivirals —active against viruses
Antiprotozoal
Antihelminthic

3

What are the types of antibacterial classifications for susceptible organisms?
2

Narrow-spectrum—drugs active against only a few microorganisms.
Broad-spectrum—active against a wide variety of microorganisms

4

How is selective toxicity achieved?
6

Inhibition of cell wall synthesis

Protein synthesis inhibitors

DNA synthesis inhibitors

RNA synthesis inhibitors

Mycolic acid synthesis inhibitors

Folic acid synthesis inhibitors

5

Protein Synthesis inhibitors: Inhibit 30s Subunit
are what classes and what drugs?
2 with three each

Aminoglycosides

Gentamicin
Tobramycin
Amikacin

Tetracyclines

Tetracycline
Doxycycline
Minocycline

6

Protein synthesis inhibitors: 50s Subunit
are what classes and what drugs?
2 with three and four drugs

Macrolides

Erythromycin
Clarithromycin
Azithromycin

Others:
Chloramphenicol
Clindamycin
Linezolid
Streptogramins

7

DNA synthesis inhibitors?
Two classes
and 6 drugs

Fluoroquinolones
Ciprofloxacin
Oflaxacin
Norfloxacin
Levofloxacin
Gatiflocacin
Moxifloxacin

Metronidazole

8

RNA synthesis inhibitors

Rifampin
TB drug

9

Folic acid synthesis inhibitors
2

Sulfonamides
Trimethoprim

10

What locations in the body are normally free of florA?
3

The blood, brain, muscle and cerebrospinal fluid are normally free of flora

11

Endocarditis
Patient history of-
Native valve: 2 and 4
IV drug user: 2 and 1
Prosthetic valve: 3 and 3
What will be the causitive agent and what antibiotic will we use?

1. Strep viridans (30-40%), “other Strep”(15-25%)
2. Pen G or
Amp + Nafcillin or oxacillin + gentamicin

1. Staph aureus (MSSA and MRSA) All others rare
2. vancomycin

1. S. epidermidis, S. aureus, S. viridans and others
2. vancomycin + rifampin + gentamicin

12

Intraabdominal infections
Diverticulitis, perirectal abscess, peritonitis: 4 and 3
What will be the causitive agent and what antibiotic will we use?

1. E Coli
2. occasionally P. aeruginosa
3. (Anerobes) Bacteroides sp.
4. Enterococci

TMP-SMX-DS (Bactrim) or Cipro or
Levofloxacin
+
Metronidazole

13

Skin and Soft Tissue Infections
Generalized cellulitis: 2 and 4
Diabetic ulcer: 3 and 3
Animal bites: 1 and 1
Necrotizing fasciitis: 2 and 5
What will be the causitive agent and what antibiotic will we use?

1.
Staph aureus
Strep
2.
Staph: MSSA: Cephalexin
Staph: MRSA: TMP-SMX-DS or Clindamycin
Strep: Cephalexin

1.
Staph (assume MRSA)
Strep (Group B) or pyogenes
2.
Doxy or TMP-SMX-DS
Or Clinda

1. Pasturella multocida (cat)
2. Amox-clav (Augementin)

1. GABS, C. perfringens
2. PCN G, cefoxitin, chloramphenicol, clindamycin, metronidazole

14

Urinary tract
What will be the causitive agent and what antibiotic will we use?
4 and 6

1.
E. Coli
Gram (-) aerobic bacilli
Enterococcus
Staph Saprophyticus

2.
TMP-SMX-DS
Nitrofurantoin
Fosfomycin

If > 20% resistance to TMP-SMX-DS then can use

Cipro, Levo, Moxi

15

Respiratory tract special considerations:
What will be the causitive agent and what antibiotic will we use?

Aspiration pneumonia: 2 and 3
Lower/hospital acquired: 2 and 4
History of HIV: 2 and 2

1.
Anaerobic and aerobic mouth flora
2. Clindamycin or Ampicillin-Sulbactam or A carbapenem

1. Pseudomonas aeruginosa
Gram(-) aerobic bacilli
2. Imipenem-cilastatin or meropenem add Ciprofloxacin or Tobramycin if suspect pseudomonas

1. Pneumocystis carinii
S pneumoniae
2. Trimethoprim-sulfamethoxazole (Bactrim, Septra)

Pentamadine

16

Respiratory Tract
What will be the causitive agent and what antibiotic will we use?
Sinusitis: 7 and 6
CAP: 3 and 4

1.
S. Pneumoniae 33%
H. Influenzae 32%
M. Catarrhalis 9%
Anarobes 6%
Grp A Strep 2%
Viruses 15-18%
S. Aureus 10%

2.
Peds: Amox or Amox-Clav
PCN allergy: Clinda
Adult: Amox-Clav
PCN allergy: Levo or Doxy


1.
All of the above plus the atypicals
Klebsiella pneum.
Mycoplasma pneum.
Chlamydia pneum.

2. Azithromycin, Clarithromycin, Doxycycline, or
Respiratory FQ (if comorbidities)

17

Meningitis in children
What will be the causitive agent and what antibiotic will we use?

Child

1.
E coli
Enterococcus spp.
GBS
Listeria monocytogenes
anerobes (bacteroides fragilis)
Gram(-) aerobic bacilli

2. Ampicillin + gentamicin


1.
Strep pneumoniae
Neisseria meningitis
Haemophilus influenzae

2. Vancomycin + cefriaxone or cefotaxime


neonates are susceptible to normal vaginal flora becoming pathogenic

18

Meningitis
Age 1 mo to 50 years: 2 and 3
Age

1.
S. Pneumoniae
Meninogococci
2. Cefotaxime or Ceftriaxone + vancomycin

1.
Group B Strep 49%
E Coli 18%
Misc Gm + 10%
Misc Gm – 10%

2. Ampicillin + Cefotaxime or Gentamycin

19

What antibiotic should be administered before the surgery begins via IV
Often used to irrigate the surgical site as well?
DOC and Alt?

Cefazolin (Ancef) 1-2 gram IV (30 minutes before skin incision)
For penicillin allergic patients can use vancomycin 1-1.5g (1 hour infusion)

20

Certain individuals are susceptible to developing bacterial endocarditis
?
2

Prosthetic heart valves
Congenital heart disease

21

Bacterial endocarditis prophylaxis?
30-60 min prior to dental procedures using what?
Whats the alternative? 3

Amoxicillin 2 grams PO

For penicillin allergy
Clindamycin 600 mg
Azithromycin 500 mg
Clarithromycin 500 mg

22

Here are a few of MANY complications from antibiotic therapy?
5

1. Toxicity
2. C. difficile diarrhea
3. Alteration of gut flora and change in vitamin K levels leading to difficulty managing warfarin therapy
4. Candida overgrowth
5. Serious side effects

23

C. Difficile diarrhea and colitis is a major complication of antibiotic therapy.
Frequent: 4
Infrequent: 4
Rare: 3

Ampicillin/amoxicillin
Cephalosporins
Clindamycin
Quniolones

Chloramphenicol
Macrolides
Sufonamides/Trimethoprim
Tetracycline

Metronidazole
Aminoglycosides
Vancomycin