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Flashcards in Bacteriostatic Antibiotics Deck (34):
1

What are macrolides?

Contain many-member lactone rings to which are attached one or more deoxy sugars

2

What is the mechanism of erythromycin?

Inhibits protein synthesis by binding to 50S ribosomal subunits of sensitive microorganisms

3

What is erythromycin most effective against?

Gram positive cocci (staph and strep), and gram positive bacilli and some gram negative

4

What happens when erythromycin passes through the first pass?

Cholestatic hepatitis - causes smooth muscle contraction as it goes through the bile duct, causing bile to back up into the liver

5

As erythromycin goes through the GI tract, it kills bacteria and causes what?

Diarrghea

6

What drug is no longer effective against oral organisms due to resistance, and are no longer often used in dentistry?

Erythromycin

7

What are the 3 reasons why we don't use erythromycin in dentistry, and is considered a red flag?

  1. Oral bugs are resistant to drugs
  2. GI side effects
  3. Dangerous drug interactions (causing seizures, other serious effects)

8

Describe clarithromycin (Biaxin)?

  • Bacteriostatic
  • Bactericidal at doses used for SBE prophylaxis (dentistry)

9

What is the drug of choice for upper respiratory tract infections, and used for STDs?

Azithromycin (Zithromax - "Z-Pack")

10

What is the half-life of azithromycin?

90 hours

11

What type of drug is clindamycin?

Lincosamide

12

What is the mechanism of action of Clindamycin?

Antibacterial - interferes with bacterial protein synthesis - inhibits peptide bond formation

13

What is an indication for clindamycin?

Orofacial infections and periodontal infections caused by anaerobic bacteria

14

What is the drug of choice for orofacial infections in penicillin allergic patients, and is also used for endodontic infections?

Clindamycin

15

What is the important preparation of clindamycin?

clindamycin HCl (Cleosin) **Know this

16

Is clindamycin broad or narrow spectrum?

Broad

17

What are some adverse effects of clindamycin?

  • Gastrointestinal - diarrhea, nausea, vomitting, etc
  • Super infection
  • Clostridium difficile --> pseudomembranous colitis

 

18

What cuases Colitis caused by C-diff?

  • Cephalosporins
  • Clindomycin

19

Why don't you want to take an anti-diarrheal agent when they have pseudomembranous colitis?

The C-diff exotoxin will continue to irritate colon, may cause ulceration/perforation allowing bacteria into peritoneum

20

The greatest number of antibiotic-associated cases of C diff diarrhea are from what?

Cephalosporins

21

What is the mechanism of action for tetracycline?

Acts on gram negative bacteria - binds to 30S ribosome = inhibits bacterial protein synthesis

22

What is tetracyclines impaired by?

Milk products, aluminum, sodium bicarbonate, divalent cations, iron

- Mechanism is chelation and increased gastric pH

23

What drug is stoed in gingical crevicular fluid, dentin and enamel of unerupted teeth (teratogenic effect)?

Tetracyclines

24

What are some adverse effects of tetracyclines?

  • Photosensitivity
  • Hepatotoxicity
  • Renal toxicity 
  • FDA Pregnancy category = D

25

What are some common preparations of tetracycline?

  • doxycycline
  • minocycline
  • tetracycline

26

What is the most used tetracycline used in dentistry and what is its mechanism of action?

doxycycline - inhibits collegenase, the enzyme that breaks down connective tissue and bone

27

What is a subantimicrobial dose that only inhibits collagenase but doesn't kill bacteria?

doxycycline hyclate (Periostat)

Atridox - subgingivally

28

What is the most potent tetracycline, and causes staining of teeth in adults?

minocycline (Minocin)

29

What is locally-applied minocycline called?

Arestin

30

Tetracyclines are contraindicated with what?

penicillins/cephalosporins

31

What are you supposed to do with tetracyclines and iron/dairy/antacids?

Wait a min of 2 hours

32

What are oral contraceptives drug interactions with antibiotics?

Hormones activated by gut flora - possibility to get pregnant 

33

What are the drug interactions with antibiotics and oral anticoagulants (warfarin)?

  • Antimicrobials kill bacteria making vitamin K 
  • No competitor for warfarin
  • Excessive anticoagulation = very thin blood!

34

What is vancomycin (Vancocin) mechanism of action?

Inhibits bacterial cell wall synthesis, different than penicillins