antibiotics in periodontal therapy

Question 1

potential indications for use of systemic antibiotics

Answer 1

• aggressive periodontits (localized or generalized forms)
• periodontal abscess (if severe)
• NUG (if severe)

Question 2

antibiotics used in periodontal therapy

Answer 2

• penicillins (amoxicillin)
• metronidazole
• tetracyclines (doxycycline)
• clindamycin
• macrolides (azithromycin, clarithromycin)

Question 3

antibiotics that inhibit dna replication

Answer 3

metronidazole and fluoroquinolones

Question 4

tetracyclines work by:

Answer 4

inhibiting 30S subunit of ribosomes (inhibit protein synthesis)

Question 5

antibiotics that inhibit the 50S ribosome subunit

Answer 5

macrolides (azithromycin and clarithromycin) and clindamycin

Question 6

antibiotics that interfere with the cell wall

Answer 6

penicillin/ amoxicillin / ampicillin

Question 7

metronidazole is an example of a ____ antibiotic

Answer 7

narrow-spectrum (effective against specific families of bacteria- preferred)

Question 8

tetracycline is an example of a _____ antibiotic

Answer 8

broad-spectrum

Question 9

penicillins are ____, but are inactivated by _____

Answer 9

bactericidal; beta-lactamases (break down the beta-lactam ring of penicillins)

Question 10

penicillins reach effective levels in _____ but don’t inhibit all _____; they also don’t penetrate _____ very well

Answer 10

gingival fluid; A.a. strains; epithelial cells

Question 11

amoxicillin has ____ spectrum, enhanced _____, and good activity against _____

Answer 11

broad; tissue penetration; gram negatives

Question 12

_____ is amoxicillin combined with a beta-lactamase inhibitor

Answer 12

augmentin

Question 13

metronidazole is a ____ spectrum _____ agent that is active against _____

Answer 13

narrow; bactericidal; strict anaerobes

Question 14

metronidazole activity against ____ bugs like Aa is less potent ; metronidazole is inexpensive and usually well-tolerated

Answer 14

facultative

Question 15

tetracyclines (minocycline and doxycycline) are ____ agents against most periodontal pathogens, with ____ activity

Answer 15

bacteriostatic; broad-spectrum

Question 16

tetracyclines can reach higher levels in ____ than in _____

Answer 16

gingival fluid; blood serum

Question 17

tetracyclines inhibit ______, which mediates collagen breakdown in periodontitis

Answer 17

collagenase

Question 18

tetracyclines are actively accumulated by _____, ____ and _____

Answer 18

oral epithelial cells; gingival fibroblasts; PMNs

Question 19

fluoroquinolones (ciprofloxacin) are _____ and extremely active against ____, less active against _____

Answer 19

bactericidal; Aa; anaerobic bacteria like Pg

Question 20

fluoroquinolones reach higher levels in GCF than in blood; penetrate ____ and ____ and can kill invasive bacteria

Answer 20

epithelial cells; phagocytes

Question 21

clindamycin has potent ____ activity against _____

Answer 21

bacteriostatic; strict anaerobes

Question 22

clindamycin is less effective against _____

Answer 22

facultative pathogens like Aa

Question 23

clindamycin penetrates ____ and can occasionally induce _____

Answer 23

bone; ulcerative colitis

Question 24

clindamycin used as an alternative antimicrobial agent in ______

Answer 24

penicillin-allergic pts

Question 25

macrolides reach high concentrations in ____ and have good activity against _____

Answer 25

tissue; Aa, Pg, and other gram negative anaerobes

Question 26

macrolides penetrate ____ and kill invasive bacteria; also taken up by ____ and _____

Answer 26

epithelial cells; PMNs and fibroblasts

Question 27

macrolides produce ______; have a simple ____ and are expensive

Answer 27

anti-inflammatory effects; regimen (one dose per day)

Question 28

common features of tetracyclines, fluoroquinolones, and macrolides

Answer 28

• levels more often higher in GCF than in blood
• drugs actively accumulated by PMNs, gingival fibroblasts, and oral epithelium; can potentially kill bacteria that have invaded/entered host cells

Question 29

empirical regimen for aggressive periodontitis or severe chronic periodontitis

Answer 29

amoxicillin (500 mg TID) combined with metronidazole (250 mg TID) for 8 days

Question 30

alternative regimens for penicillin-allergic patients

Answer 30

• azithromycin (500 mg starting dose, then 250 mg per day for 4 days)
• metronidazole (500 mg TID for 7 days)

Question 31

limitations of systemic antibiotics in perio

Answer 31

• antibiotics are not beneficial in the treatment of periodontitis if given without SRP (when used as a monotherapy)
• antibiotics can have undesirable side effects when given systemically

Question 32

adverse side effects associated with systemic antibiotics

Answer 32

• induction of antibiotic resistance, which undermines our ability to continue using current antibiotics
• induction of microbial overgrowth
• hypersensitivity or toxicity (allergy, nausea, diarrhea, photosensitivity)

Question 33

frequent adverse effects of penicillins

Answer 33

rashes, allergy, diarrhea

Question 34

frequent adverse effects of tetracyclines

Answer 34

nausea, diarrhea, dental staining

Question 35

frequent adverse effects of metronidazole

Answer 35

nausea, diarrhea, altered taste, antabuse effect

Question 36

frequent adverse effects of clindamycin

Answer 36

rashes, nausea, diarrhea

Question 37

frequent adverse effects of azithromycin

Answer 37

diarrhea, nausea, cholestatic jaundice (rare), cardiac arrhythmia (rare)

Question 38

current application for controlled release local antibiotic delivery

Answer 38

treatment of localized recurrent periodontitis in cases that are otherwise stable