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Pharm Spring 2014 > Antimicrobials > Flashcards

Flashcards in Antimicrobials Deck (48)
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1

If a patient is severely immunocompromised, what type of antibiotic should you give them?

Bactericidal

2

Without our normal flora, we can be exposed to

Superinfections. Our normal flora competes with pathogens for nutrients and secrete substances that can kill opportunistic bacteria

3

When might you not want to give antibx?

If the person is allergic and the surgery has low risk for infection

4

The prophylactic antibiotic should be given no earlier than _____

1 hour before surgery

5

Does a brief course of antibiotics result in resistant organisms?

There is no evidence of this. Peri-operatively we usually only give 1 dose, but may be continued up to 48 hours post-op

6

Do we usually give broad or narrow antibx?

Anesthesia usually gives broad. The antibx will depend on pt tolerances and location of the surgery

7

Do antibiotics cross the BBB?

Highly variable

8

When might the surgeon want you to hold off on the antibiotics?

If pt is in OR for a wound cleaning (remember that antibiotics are more effective if infected material is removed!)

9

Are hypersensitivity reactions from antibiotics dependent or independent of dose?

Independent

10

Things to keep in mind with parturients

Most antimicrobials cross the placenta and enter breast milk. Also concern for teratogenecity.

11

Considerations for the elderly

Renal and liver impairment
Decreased plasma protein (higher free fraction)
Reduced gastric motility and acidity
Increased body fat

12

Which is better absorbed from the GI tract, ampicillin or amoxicillin?

Amoxicillin! (think of Moxi)

13

Renal excretion of Penecillin

90%

14

MOA for penicillin?

Interferes with cell wall synthesis and stability

15

These antimicrobials belong to the beta-lactam family

Penicillins, cephalosporins,

16

Only these antimicrobials are bacteriostatic

Tetracyclines, macrolides (can be either), lincomycins, and sulfonamides

17

How are viruses classified?

By if they contain DNA or RNA. They never contain both!!

18

This HIV protease inhibitor is the most potent inhibitor of the cytochrome P-450 system

Ritonavir

19

Acyclovir and Valacyclovir

Antivirals for herpes. Excreted by the kidneys.

20

Vidarabine

Antiviral for cytomegalic inclusion disease and HSV encephalitis. This antiviral is mutagenic and carcinogenic.

21

Famciclovir

Antiviral for acute herpes zoster (shingles)

22

Ganciclovir

Antiviral for CMV. Risk of hematologic toxicity

23

Amantadine

Antiviral for Influenza A. Renally excreted.

24

Antibiotic that inhibits the P-450 system

Cipro (fluoroquinolone)

25

Antibiotic that induces the P-450 system

Rifampin

26

Antibiotic whose MOA is bactericidal by acting on DNA and RNA polymerase

Rifampin

27

This antibiotic has the most potent effect at the NMJ

Polymyxin B and Colistimethate. These are mostly prejunctional, and potentiate with NDNMBs. Not reliable reversed with neostigmine or calcium.

28

This antibiotic can cause pseudomembranous colitis

Clindamycin

29

This antibiotic can treat pseudomembranous colitis

Flagyl (even when caused by clinda)

30

Example of an antifungal

Amphotericin B.

31

Biggest risk of amphotericin B

Renal impairment. 80% of people will experience renal impairment. Most recover, but some have permanent reduction in GFR. Follow plasma creatinine.

Amphotericin B is a terrible bitch to your kidneys

32

Method of action for antivirals (interferons)

1) Binds to receptors on host cell membranes, causing production of enzymes that inhibit viral replication and degrade viral RNA
2) Enhances tumoricidal activity of macrophages

33

Biggest symptom of interferons

Flu-like symptoms

34

Three different mechanisms of antivirals for AIDS

1) Nucleoside reverse transcriptase inhibitors (impostor host cells)
2) Non-nucleoside reverse transcriptase inhibitors (inhibits the function of enzymes used by the virus)
3) Protease inhibitors (binds to HIV protease)

35

Effect of protease inhibitors on the P-450 system

Inhibits the P-450 system.

36

Which protease inhibitor is the most potent inhibitor of the P-450 system?

Ritonavir

37

MOA of penicillins

Interferes with enzymes responsible for cell wall construction and stability

38

Main method of excretion of macrolides

Bile

39

How to remember macrolides.

Remember the erythromycin is a macrolide. We used this to increase gastric emptying. Therefore, the main SE of this is GI intolerance (Cramping, N/V/D, especially with IV infusion). Also with GI stuff, it is excreted through bile and is metabolized by the P-450 system.

40

SE of erythromycin

GI intolerance (cramping, N/V/D) especially with IV infusion, QT prolongation, and thrombophlebitis with prolonged IV use.

41

Ciprofloxacin has a ________ effect on the P-450 system and has an elimination half time of _____

Inhibitory
3-8 hours

42

SE of Cipro

Minimal SE. Mild GI disturbance

43

All GPCRs will undergo _____

Desensitization

44

MOA of ciprofloxacin

Interfering with the enzyme responsible for maintaining the helical structure of DNA

45

Adverse effects of sulfonamides

Increases the effects of PO anticoagulants, skin rash to anaphylaxis, drug fever, hepatotoxicity, and rare incidence of hemolytic anemia

46

Polymyxin B and Colistimethate have mostly (pre/post) junctional effects on the NMJ

Mostly prejunctional ("B"efore the synapse!)

47

With what antibiotic class do you want to measure coags?

Sulfonamides

48

Is rifampin able to cross the BBB?

Hellz to the yea