Antibiotics

Question 1

oral flora colonization

Answer 1

happens during birth, breastfeeding, interactions with adults
a few days after birth: strep species (s salivarius)
around tooth eruption: more strep like s mutans and sanguis
Actinomyces, bacteroids, fusobacterium: associated with perio sidease
puberty: spirochetes

Question 2

common oral infections:

Answer 2

pulpal
maxillofacial and salivary
perio infections
oral malodor

Question 3

closing the right Ab:

Answer 3

selective toxicity: harmful to the bacteria but safe for the host
activity and concentration: distinguish between bactericidal and bacteriostatic. when used in combination having one of each gives an antagonistic effect
determine sensitivity when possible
dosing:
concentration dependent drugs: increased activity by increasing concentration
ex: metronidazole, quinolone
time dependent: increasing concentration doesn’t increase activity
ex: penicillin, cephalosporin

Question 4

Tx considerations:

Answer 4

have a diagnosis
use the correct spectrum (start as narrow as possible)
high dose, short duration
keep taking 48 hrs after symptoms subside
intervals according to drug half life
adjustments for pts with hepatic and kidney disease
consider resistance

Question 5

pulpal infections:

Answer 5

gram + and - facultative anaerobes

strep pyogens, strep viridans and nisseria

Question 6

perio infections:

Answer 6

gram - and + anaerobes and fungi

actinomycetes, spirochetes, bacteroids, fusobacteria, candida

Question 7

salivary infections and osteomyelitis:

Answer 7

staph

Question 8

classes of Abs:

Answer 8

cell wall synthesis 
cell membrane
protein synthesis 
nucleic acid synthesis
intermediary metabolism

Question 9

cell wall synthesis:

Answer 9

penicillin, vancomycin (+)
cephalosporin, carbapenems
most common
vancomycin and carbaoenems reserved for resistant infections

Question 10

cell membrane:

Answer 10

polymyxins (usually topical)

antifungals

Question 11

protein synthesis

Answer 11

clindamycin, macrocodes (+)
tetracycline

bacteriostatic
exertion via both kidney and liver
erythromycin has poor bioavailability
Tetracyclines bind to Ca; inhibited by anti-acids & dairy, not used in pregnancy

Question 12

nucleic acid synthesis:

Answer 12

fluoroquinolone
metronidazole, cirprofloxican (-)

metronidazole interferes with anticoags

Question 13

intermediary metabolism:

Answer 13

sulfonamides

trimethoprim

Question 14

beta lactam:

Answer 14

penicillin: narrow spectrum. g: injectable
strep, staph, pneumonias. resp infections, pneumonias, gonorrhea, syphilis, skin and soft tissue infections
b lactam resistance: clavulanic acid, oxacillin, methicillin, cloaxacillin
extended spectrum: HELPSE (Haem influenza, e-coli, listeria, proteus, salmonella, enterococci)
cephalosporins: broad spectrum. hospital and GI infections

all cleared through renal system

Question 15

tx of pulpal infections:

Answer 15

soft tissue involvement:
penicillin, amoxicillin, clindamycin

facial space swelling: abs against anaerobes
metronidazole, clindamycin
klepsiella: cephalosporin

Question 16

tx of salivary gland infections:

Answer 16

broad spectrum like tetracycline or cephlaxin

Question 17

perio therapy

Answer 17

tetracycline: broad spectrum, for aggressive, refractory, and juvenile disease
doxycycline: long acting. greatest anti collagenase activity
metronidazole: good for anaerobes. narrow spectrum. used to treat NUG
clindamycin: narrow spectrum. good for refractory cases

Question 18

LGE tx:

Answer 18

chx gluconate: bis biguanide. causes staining and calculus accumulation LT
povidone iodine 10%: bacteria, fungi, and viruses