Antimicrobials Flashcards
Describe antimicrobials VS antibiotics.
- Antimicrobial
-natural, semi synthetic or synthetic origin that kills or inhibits growth of microorganisms but causes little/no damage to host - Antibiotic
-chem substance made by microorganism that has capacity in dilute solution to selectively inhibit the growth or kill other microorganisms
>made by soil dwelling organisms
>old natural molecule
>communicate between diff microorganisms
>inhibit potential competitive microorganisms
Describe the ideal qualities of an antibiotic.
- Kill/inhibit growth of microorganism
- Little/no damage to host
- No allergic reaction to host
- Remain in specific bod tissue in host long enough to be effective
- Stable when stored in solid or liquid form
- Target pathogen before they mutate or become resistant to it
Describe antibiotic development pipeline.
Describe the chemical structure of antibacterial agents.
- B Lactams
-beta Lactam ring - Aminoglycosides
-amino sugar substructure - Tetracyclines
-4 adjacent cyclic hydrocarbon ring - Macrolides
-14, 15, or 15-membered macrolide ring - Sulfonamide
-sulfonamide group - (Fluoro)Quinolones
-fused aromatic rings w carboxylic acid group
Describe the mode of action.
Describe the antimicrobial effect.
- Bactericidal = death & disruption of bacterial cell
-reduce # of viable cells
-preferred for serious infections or immunocompromised
-act on cell wall syn, cell membrane, DNA syn - Bacteriostatic = inhibit growth & multiplication of bacteria
-require IS to further clear infection
-inhibit protein syn & pathways
*some drugs can be either depending on:
~drug conc, presence of other drugs, bacterial species
Describe how we can reach the desired antimicrobial effect in the body of host at infection site.
-ADME principle of drug delivery
-solubility of drug at target site
>chemical & physiological processing in the bod
>chem properties of drug
-host factors
-combination therapy of drugs
>inc efficacy & spectrum
>synergic effect
*bacteriostatic drugs need growth to stop & bactericidal drugs need growth to act = antagonism
Describe pharmacokinetic/pharmacodynamic (PK-D) model.
Describe spectrum of activity.
Describe antibiotic selection.
Describe rational antimicrobial use.
-actions that prevent/min development of resistance in strain causing infection in patient commensal microbiota w/o impacting clinical efficacy
1. (Systemic) antimicrobial
-reduce overall antimicrobial consumption
2. Choice of drug
-prudent use of 2nd line, imp antimicrobials
3. Culture
-improve use of diagnostic testing
4. Which drug dosage
-optimize dose regime
Describe antimicrobial stewardship.
-coordinated interventions/program to improve & measure use of antimicrobials by promoting selection of optimal antimicrobial drug regimen, dose, duration of therapy, route of administration
Describe the traffic light antimicrobial principle.
Ranks antimicrobials according to OIE & WHO:
1. Red
-antimicrobial in vet med of high imp
-most appropriate
-culture & sensitivity testing
2. Yellow
-antimicrobial of diff class or special features
-human therapy
-not used where efficacy is in doubt
3. Green
-recommended against known susceptible organisms
-not used where efficacy is in doubt
-known actions, 1st choice
Describe the use of antimicrobials of skin infections & otitis in dogs.
Antimicrobial?
-surface pyoderma = NO
-superficial pyoderma = only if topical treatment fails or not possible
-deep pyoderma = YES
-otitis = if evidence of ruptured tympanic membrane or otitis media (not tumor, or hair, etc)
Describe cultures for skin infections & otitis in dogs.
Recommended:
-no response to therapy
-prev antibiotic treatment
-relapse or reinfection
-immunocompromised
-life threatening infection
-risk of MDR
-high AMR
-long treatment
