antibiotics in periodontal therapy Flashcards
potential indications for use of systemic antibiotics
- aggressive periodontits (localized or generalized forms)
- periodontal abscess (if severe)
- NUG (if severe)
antibiotics used in periodontal therapy
- penicillins (amoxicillin)
- metronidazole
- tetracyclines (doxycycline)
- clindamycin
- macrolides (azithromycin, clarithromycin)
antibiotics that inhibit dna replication
metronidazole and fluoroquinolones
tetracyclines work by:
inhibiting 30S subunit of ribosomes (inhibit protein synthesis)
antibiotics that inhibit the 50S ribosome subunit
macrolides (azithromycin and clarithromycin) and clindamycin
antibiotics that interfere with the cell wall
penicillin/ amoxicillin / ampicillin
metronidazole is an example of a ____ antibiotic
narrow-spectrum (effective against specific families of bacteria- preferred)
tetracycline is an example of a _____ antibiotic
broad-spectrum
penicillins are ____, but are inactivated by _____
bactericidal; beta-lactamases (break down the beta-lactam ring of penicillins)
penicillins reach effective levels in _____ but don’t inhibit all _____; they also don’t penetrate _____ very well
gingival fluid; A.a. strains; epithelial cells
amoxicillin has ____ spectrum, enhanced _____, and good activity against _____
broad; tissue penetration; gram negatives
_____ is amoxicillin combined with a beta-lactamase inhibitor
augmentin
metronidazole is a ____ spectrum _____ agent that is active against _____
narrow; bactericidal; strict anaerobes
metronidazole activity against ____ bugs like Aa is less potent ; metronidazole is inexpensive and usually well-tolerated
facultative
tetracyclines (minocycline and doxycycline) are ____ agents against most periodontal pathogens, with ____ activity
bacteriostatic; broad-spectrum
tetracyclines can reach higher levels in ____ than in _____
gingival fluid; blood serum
tetracyclines inhibit ______, which mediates collagen breakdown in periodontitis
collagenase
tetracyclines are actively accumulated by _____, ____ and _____
oral epithelial cells; gingival fibroblasts; PMNs
fluoroquinolones (ciprofloxacin) are _____ and extremely active against ____, less active against _____
bactericidal; Aa; anaerobic bacteria like Pg
fluoroquinolones reach higher levels in GCF than in blood; penetrate ____ and ____ and can kill invasive bacteria
epithelial cells; phagocytes
clindamycin has potent ____ activity against _____
bacteriostatic; strict anaerobes
clindamycin is less effective against _____
facultative pathogens like Aa
clindamycin penetrates ____ and can occasionally induce _____
bone; ulcerative colitis
clindamycin used as an alternative antimicrobial agent in ______
penicillin-allergic pts
macrolides reach high concentrations in ____ and have good activity against _____
tissue; Aa, Pg, and other gram negative anaerobes
macrolides penetrate ____ and kill invasive bacteria; also taken up by ____ and _____
epithelial cells; PMNs and fibroblasts
macrolides produce ______; have a simple ____ and are expensive
anti-inflammatory effects; regimen (one dose per day)
common features of tetracyclines, fluoroquinolones, and macrolides
- 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
empirical regimen for aggressive periodontitis or severe chronic periodontitis
amoxicillin (500 mg TID) combined with metronidazole (250 mg TID) for 8 days
alternative regimens for penicillin-allergic patients
- azithromycin (500 mg starting dose, then 250 mg per day for 4 days)
- metronidazole (500 mg TID for 7 days)
limitations of systemic antibiotics in perio
- 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
adverse side effects associated with systemic antibiotics
- induction of antibiotic resistance, which undermines our ability to continue using current antibiotics
- induction of microbial overgrowth
- hypersensitivity or toxicity (allergy, nausea, diarrhea, photosensitivity)
frequent adverse effects of penicillins
rashes, allergy, diarrhea
frequent adverse effects of tetracyclines
nausea, diarrhea, dental staining
frequent adverse effects of metronidazole
nausea, diarrhea, altered taste, antabuse effect
frequent adverse effects of clindamycin
rashes, nausea, diarrhea
frequent adverse effects of azithromycin
diarrhea, nausea, cholestatic jaundice (rare), cardiac arrhythmia (rare)
current application for controlled release local antibiotic delivery
treatment of localized recurrent periodontitis in cases that are otherwise stable
