Antibiotic Drugs - EXAM 2

Question 1

What is the MOA for beta-lactam Abx?

Answer 1

• inhibit bacterial cell wall synthesis

Question 2

What are 3 examples of Beta lactam abx?

Answer 2

• pencilillins
• cephalosporins
• carbapenems

Question 3

PCN - beta lactam

Why does resistance develop?

Answer 3

• beta-lactamase enzyme over time

Question 4

PCN - beta lactam

What bacteria is PCN the DOC for?

What types of infections?

Answer 4

• streptococci
• meningococci
• pneumococci
  mostly gram +
• skin infection, catheter infections, URI

Question 5

PCN- beta lactam

What are 4 PCN drugs?

Answer 5

• Pencillin G
• methicillin
• Nafcillin
• Amoxicillin

Question 6

PCN - beta lactam

Adv. Reactions of PCNs?

Answer 6

• hypersensitivity
• GI upset - lg. doses
• vaginal candidiasis - fungal overgrowth

Question 7

Cephalosporins - Beta Lactam

Is there resistance?

Answer 7

• not as much as w/ PCN
• broader spectrum than PCN

resistance can occur w/ the PCN-binding protein altering its structure

Question 8

Cephalosporins - Beta Lactam

What are Cephalosporins the DOC for?

Answer 8

surgical prophylaxis
* can be used w/ PCN allergy (if not anaphyl.)

Question 9

Cephalosporins - Beta Lactam

1st gen drugs:

Answer 9

Cefazolin (Ancef)
does not cross BBB
* gram + (staph, strept.)
* cellulitis, abscesses, UTI, URI

Question 10

Cephalosporins - Beta Lactam

2nd gen drugs:

gram coverage:

uses:

Answer 10

Cefuroxime (Ceftin, Zinacef)
Cefoxitin (Mefoxin)
Cefotetan (Cefotan)
gram -

Uses: H-inf. pneumonia, UTI, otitis media

Question 11

Cephalosporins - Beta Lactam

3rd gen drugs:

gram coverage:

Uses:

Answer 11

Cefotaxime (Claforan)
Ceftriaxone (Rocephin)
Ceftazidime (Fortaz)
some cross BBB

• gram -
• Uses: resistance, meningitis

Question 12

Cephalosporins - Beta Lactam

4th gen drugs:

Uses:

Answer 12

Cefepime (Maxipime)
* most resistant to beta-lactamase
* penetrates BBB well
* uses: multi-resistant organisms

Question 13

Cephalosporins - Beta Lactam

Adv. Reactions?

Answer 13

• hypersensitivity - not common
• potential production deficit of Vit. K
• do not use in clotting disorders

Question 14

What Abx do we use in the case of true anaphylaxis to beta-lactams?

Answer 14

1. Vancomycin
2. Clindamycin

Question 15

Carbapenem - Beta Lactam

Will resistance happen?

Answer 15

• prob not - can inhibit beta-lactamase enzyme

most broad spectrum of all beta-lactams

Question 16

Carbapenem - Beta Lactam

What bacteria does it work against?

Uses:

Answer 16

gram -
* P. Aeruginosa
* Enterobacter
uses:
* last line: intra-abdominal, resistant UTI, pneumonia, ruptured bowel

Question 17

Carbapenems - Beta Lactam

Does it penetrate BBB?

Drugs Examples:

Answer 17

most penetrate BBB

• Ertapenem (Invanz)
• Merropenem (Merrem)
• Imipenem (Primaxin)

Question 18

Carbapenem - Beta Lactam

Adv. Reactions?

Answer 18

• n/v
• diarrhea
• rash
• injection site rxn

Question 19

What Abx class do we not want to give to pts on Depakote?

Answer 19

• Carbapenems - Beta Lactam
• causes decreased Depakote levels by up to 90% = seizure

Question 20

Vancomycin

MOA:

Answer 20

• inhibits cell wall synthesis
• prevents bacteria from dividing & replicating
• only works if bacteria are dividing

Question 21

Vanco

Gram coverage?

What infections is it good for?

Answer 21

gram +
* blood stream infections
* endocarditis (valvular, cardiopulm. bypass) - caused by MRSA

Question 22

Vanco

Adv. Reactions?

Answer 22

frequent
* phblebitis @ inj. site
* chills, fever
* nephrotoxic - peak/trough
* “red man” syndrome - flushing, redness, inflammation

Question 23

Aminoglycosides

MOA:

Answer 23

• inhibits ribosomal proteins
• so mRNA misreads & bacteria can’t replicate
• synergistic w/ beta-lactams & vanc

Question 24

Aminoglycosides

Drugs:

Answer 24

• Gentamycin
• Neomycin

Question 25

# Aminoglycosides Adv. Reactions?

Answer 25

* **ototoxic** - give slow * nephrotoxic * curare-like effect

Question 26

# Aminoglycosides What factors increase the risk of nephrotoxicity w/ aminoglycosides?

Answer 26

* elderly * renal insufficiency * dosing > 5 days * higher doses * loop diuretics

Question 27

# Aminoglycosides What causes the curare-like effect?

Answer 27

* interference w/ Ach receptors * seen w/ depolarizer Succ

Question 28

# Fluoroquinolones MOA:

Answer 28

* inhibit DNA protein synthesis

Question 29

# Fluoroquinolones Gram coverage? indications?

Answer 29

**gram -** * GU surgery * UTI, bacterial diarrhea, bone/joint infection

Question 30

# Fluoroquinolones Drugs:

Answer 30

* Ciprofloxacin (Cipro) * Levofloxacin (Levaquin)

Question 31

# Fluoroquinolones Adv. Reactions?

Answer 31

* n/v/d * **prolonged QT** * **cartilage damage/tendon rupture**

Question 32

# Fluoroquinolones What 3 factors are associated w/ cartilage damage/tendon rupture?

Answer 32

1. renal insufficiency 2. concurrent steroid use 3. advanced age

Question 33

# Metronidazole MOA/Class:

Answer 33

Class: antiprotozoal/anaerobic antibacterial MOA: forms toxic byproducts that cause unstable DNA molecules, limiting bacteria ability to proliferate

Question 34

# Metronidazole indications:

Answer 34

* intra-abdominal infections * vaginitis * c-diff

Question 35

# Metronidazole Adv. rxns?

Answer 35

* nausea * peripheral neuropathy (long use) * **dilsurfiram like effect - hangover w/ alcohol** = flushing, dizziness, HA, chest/abd. pain

Question 36

Cefazolin Dosing * < 80kg: * 81-119kg: * > 120kg: re-dose time:

Answer 36

* 1g * 2g * 3g 4 hrs

Question 37

Vancomycin dosing

Answer 37

15mg/kg