Antimicrobials Flashcards
antimicrobials are…
Drugs that kill or inhibit the growth of microorganisms
what are the ways antimicrobials affect microorganisms? (4)
- bactericidal
- bacteriostatic
- virucidal
- fungicidal
what route of administration can antimicrobials be given? (3)
- orally
- parenterally,
- topically
what are the groups of antimicrobials? (2)
- Drugs for external application
2. Drugs for internal administration
what are the types of antimicrobials for external application? (2)
Disinfectants
and
antiseptics
what are disinfectants and antiseptics?
chemical agents
what are disinfectants and antiseptics used for?
to decrease microbe numbers in the environment
how do disinfectants and antiseptics agent vary?
- spectrum of activity
- environmental condition required for proper use
- individual characteristics
what are the types of anitmicrobials intended for internal application? (2)
antibiotics
and
antifungals
what are the requirments for successful use? (3)
- Microorganism be susceptible to antimicrobial
- Antimicrobial reach site of infection in high enough concentrations
- Animal tolerate antimicrobial and its side effects
what is antibiotic susceptibility?
the effectiveness of an antibiotic in inhibiting the growth of bacteria
how is antibiotic susceptibility measured?
minimum inhibitory concentration (MIC)
what is antibiotic resistance?
bacteria’s ability to not be affected by an antibiotic
how can antibiotic resistant occur? (2)
- can be the result of genetic mutations in individual bacteria that are passed on to future generations
- inappropriate administration of antibiotics
what are the mechanisms by which antimicrobials affect bacteria?
- inhibit cell wall formation
- change the permeability of the cell membrane
- inhibit protein synthesis
- interfere w/ metabolism
- damage bacterial DNA or RNA
what are some antibiotic drugs? (8)
Penicillins Cephalosporins Aminoglycosides Quinolones Tetracyclines Chloramphenicol Lincosamides Sulfonamides and Potentiated Sulfonamides
what antibiotic was the first widely used antibiotic?
penicillin
when was penicillin developed?
1940’s
how does penicillin affect bacteria?
formation of bacterial cell wall in actively growing bacteria
how can penicillin be administered? (2)
oral
and
parenteral
which penicillin is not absorbed well orally
Pen. G
which penicillin should be given with food?
amoxicillin
what tissue is penicillin not distributed to?
CNS
what form is penicillin eliminated in?
unchanged
what treatment is penicillin great for?
urinary tract infections
what is penicillins spectrum of activity? (2)
G+ bacteria
anaerobic bacteria
what do penicillin resistant G+ bacteria secrete?
β-lactamase enzyme
what does the β-lactamase enzyme do to penicillin?
disrupts the structure of the penicillin molecule
what drug can inactivate β-lactamase enzyme? (2)
Clavulonic Acid
and
Sulbactum
what are some possible allergic reactions with penicillin?
- fever
- swollen lymph nodes
- facial swelling
- skin rash
- shock
what are some concerns with oral administration?
Possible anorexia, vomiting, diarrhea
which antibiotics can cause superinfection in guinea pigs? (2)
- Penicillin
2. Lincosamide
which antibiotic has similar properties as penicilin?
Cephalosporins
which cephalosporin is a Semi-synthetic, broad spectrum injectable?
Convenia (cefovecin)
how long are the effects of Convenia (cefovecin)?
2 weeks
what is convenia effect against in dogs and cats?
skin issues
what is convenia effective against in cats?
UTI
which bacteria is convenia not effective against?
pseudomonas
which cephalosporin is administerd SID for skin infectinons?
Cefpodoxime (Simplicef)
how does penicillin affect bacteria?
Inhibit the formation of the cell wall in actively growing bacteria
which antibiotics should penicillin not be given with?
bacteriostatic antibiotics
what must be observed in food animals given penicillin?
withdrawal times
how can cephalosporins be administered? (2)
parenteral
or
oral
what can cause cephalosporins to be absorbed slowly?
presence of food
what tissue is cephalosporins not distributed to?
CNS
what form is cephalosporins excreted in?
unchanged or change
how is cephalosporins metabolized and eliminated? (2)
liver
and
kidney
what is the spectrum of activity for first generation cephalosporines?
G+ bacteria
what is the spectrum of activity for second and third generation cephalosporines?
G+ and some G- bacteria
which bacteria is cephalosorines ineffective against?
G+ that secretes β-lactamase enzyme
what are some possible allergic reactions with cephalosporines? (5)
fever swollen lymph nodes facial swelling skin rash shock
what may happen when injecting cephalosporins IM?
pain
what can giving cephalosprins orally cause?
vomiting, diarrhea, and anorexia
which antibiotics should you not use cephalosporins with?
bacteriostatic antibiotics
what can happen if overdosed with cephalosporins?
Potentially toxic to kidneys
what should be observed with cephalosporins?
Observe withdrawal times
which antibiotic has ver long withdrawal times?
aminoglycosides
which antibiotic is a very powerful G-
antibiotic?
aminoiglycoside
what animal considerations are aminoglycosides not used in?
food animals