1.7 clinical uses of abx

what is the most likely explanation for increasing abx resistance in community-acquired disease?

A. pts not completing Rx therapy

B. Gr - outer membrane permeability

C. generic branding and import medicines

D. overuse of abx in farming and industry

E. Metronidizole resistant spore forming anaerobes

D

(key is community-acquired)

what are the characteristics of ideal abx agents

-bacteriocidal

-long half life

-low binding to plasma proteins

-oral and injected preparations (rather than just inj)

-good tissue distribution

-minimal side effects or interactions

-"narrow spectrum"

define what a "narrow spectrum" abx is

highly targeted

are oral or injected abx preferred

oral

what is one drug example that has a "narrow spectrum"

penicillin V

abx resistance typically occurs within _______ _______

several years

were genes coding for abx resistance present before or after humans began producing abx

before

what was the purpose of Joshua Lederberg's 1952 "Replica Plate" experiment

demonstrate mutations (resistance) in bacteria can occur before they are exposed to selective pressures (ie abx)

carbapenem is a _____-_____ abx with a _____ _____ activity against bacteria resistant

beta-lactam; broad spectrum

in an ideal situation you are able to ID bacteria, _____ __ _____, and then ______. Does this always happen?

test for sensitivity; prescribe; no often you are unable to test for sensitivity

what are some sensitivity tests/categories that might be tested for?

what type of test is used to test for resistance or sensitivity

disc diffusion

define minimum inhibitory concentration

define minimum bactericidal concentration

should abx be rx for upper respiratory tract infections? why or why not?

no; half of these infections could be a viral source

in what cases are upper respiratory tract infections of a bacterial cause?

10+ days and advanced sinusitis

if pt's do not respond or progress within ______ of taking abx, they should be referred to an ID specialist

24hrs

in what cases should pt's always be referred back to their MD or to specialist prior to tx with abx?

pts with hx of prosthetic heart valves or endocarditis

most oral-facial infections are ______ ______ that are not often ____-_____ resistant

mixed anaerobes; beta-lactam

clinical situations that require abx are often accompanied by what other symptoms?

elevated body temp, swelling, restricted jaw movement

what situations automatically require rx of abx

-facial cellulitis

-acute necrotising ulcerative gingivitis

-lateral periodontal abscess

-acute pericoronitis with systemic signs

facial cellulitis may often be associated with?

dysphagia and development of septicemia

specifically in dentistry, antimicrobials are used prior to surgery in what cases/situations?

-risk of post op inf is high

-compromised immune system

-contaminated wounds

-consequence of potential infection is life threatening

what 4 conditions were listed where abx are still recommended prophylactically for dental visits

-artificial heart valves

-prev endocarditis

-congenital heart cond

-heart transplant

are abx still required for pts with joint replacements

no

in what cases/conditions are abx no longer recommended prophylactically for dental visits

-mitral valve prolapse

-rheumatic heart disease

-bicuspid valve disease

______ are prophylactically used when someone is allergic to penicillin

macrolides

(azithromycin or clarithromycin)

which abx are the most commonly used by dentists

beta lactams

penicillin G

penicillin V

in what cases would metronidazole be used

-against anaerobic bacteria

-pts with perio disease

metronidazole is _____ ______ and has _____ ______

well absorbed; low resistance

is drinking recommended when taking metronidazole

no

consider metronidazole if no improvement within _____ after taking penicillin

48 hrs

clinical uses of metronidazole

-acute ulcerative gingivitis

-rapidly progressing periodontal disease

-anaerobic infection around erupted wisdom teeth

why is clindamycin no longer rx as an alternative if someone has a penicillin allergy?

increased risk for C.diff.

after macrolides, what is the 3rd best option as a substitute to penicillins

quinolones

(ciprofloxacin, levofloxacin)

can young children or pregnant women use tetracyclines

no

tetracyclines inhibit ____ _______ ______

30S ribosomal subunits

tetracyclines may still be a drug of choice for some _______ or ______ ______ intracellular bacterial infections

chlamydial; mycoplasma obligate

chlorhexidine can be used for?

gingivitis, periodontitis, dental traumas, oral cysts, post extraction

chlorhexidine primarily used to reduce ______

plaque

fluoride reduces cavities up to ____-_____%

20-60

what is the systemic effect of fluoride

what is the topical effect of fluoride

what is the antimicrobial effect of fluoride

fluoride inhibits ______ of bacterial glycolytic enzymes

enolases

what is recommended for pts to take while on abx to prevent C. diff?

probiotics

(which includes saccharomyces boulardii)