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Micro Exam #2 > Antibiotics > Flashcards

Flashcards in Antibiotics Deck (86)
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1

Three desired properties of antibiotics

Broad Range (until + diagnosis)
Able to get to body tissues
Selectively Toxic

2

Give an three examples of a synergistic antibiotic interaction.

SxT will block sequential steps
Cell Wall/Membrane Inhibitors may allow drug entry
One drug may inhibit detox enzymes

3

Give three reasons for use of multiple antibiotic drugs

Systemic/multiple infections
Delaying resistance to long-term use
Synergisms

4

Three categories of patients that should be prescribed prophylactic antibiotics.

Known contact with a known agent
Before surgery with high likelihood of complications
Special Cases -- ex. predisposed to endocarditis, UTI, immunocompromised

5

How do new biofilm preventing coatings work?

Implanted devices are coated with a cationic detergent that interacts with the quaternary amine

Over the next several days, hydrolysis occurs and releases dead cells

6

What is fidaxomicin active against?

Inhibits RNA polymerase
G+

7

What is Bedaquiline active against?

c Subunit of ATP synthase rotor
Mycobacteria

8

Why is amoxicillin rarely prescribed alone?

Heightened resistance to the drug

9

Three primary types of cell wall inhibitors?

beta-lactams
Bacitracin
Glycopeptides (Vancomycin, Telavancin)

10

How do beta-lactams work?

Inhibit transpeptidation and activate autolysins in the cell wall

11

How do bacteria resist beta lactams?

beta-lactamases, lack of PBPs, autolysin mutations

12

What drugs are often given with beta lactams?

Beta lactamase inhibitors (Clavulinic acid, aulbactam, tazobactam)

13

Which penicilins are natural? Why use them?

Pen G, Pen V
Best vs. Gram + bacteria

14

Which penicillins are expanded spectrum? (i.e. also good against Gram -)

Ampicillin
Piperacillin
Mezlocillin

15

Which Penicillins are beta-lactamase resistant? (3)

Nafcillin
Oxacillin
Cloxacillin

16

Which penicillins are acid resistant?

Amoxycillin
Pen V
Oxacillin

17

Three most common penicillin +lactamase inhibitor combos

Augmentin = amoxicillin + Clavulanic acid
Ampicillin + Sulbactam
Zosyn/Tazomed = Piperacilin + Tazobactam

18

Which beta lactam structure provides some natural resistance to beta-lactamase?

Monobactams
(beta-lactam with one ring)

19

Three types of beta lactams?

Penicillins
Cephalosporins
Monobactams

20

Perks of 3rd and 4th generation cephalosporins?

Work on Gram +/-
Can Cross BBB

21

Examples of 3rd and 4th gen cephalosporins?

Ceftazidime, Cephotaxime, Caphtriaxone
Cefepime

22

Two downsides to monobactams

Effective vs G- only
Expensive

23

name a monobactam

Aztreonam

24

Pro and con of carbapenems?

Broad spectrum
Possibly toxic (leads to seizures)

25

Common problem with beta lactams?

Allergy (Pen>Ceph>Mono)

26

How does bacitracin work?

Blocks the de-phosphorylation of bactoprenol

27

When would you use bacitracin?

Topical
Almost only vs. G+

28

Side effects of bacitracin

Poor absorption
Renal Toxicity

29

Why is bacitracin so hard to absorb?

Its freakin huge

30

How do antibiotic glycopeptides (vancomycin, telavancin) work?

Bind to the end of amino acid side chain, blocking transglycosylation and transpeptidation.