Practice Questions Flashcards
Which 3 antibiotic classes are LIPOPHILIC and can gain access to intracellular location as well as protected sites?
- FQs
- Phenicols
- Nitroimidazoles
Others: tetracyclines, macrolides, lincosamides, and pot. sulfas do NOT gain access to protected sites.
what 2 antibiotic classes are HYDROPHILIC?
- Beta lactams (penicillins and cephalosporins)
- Aminoglycosides
Give the MOA for the following antibiotic classes:
Beta-Lactams:
Aminoglycosides:
Tetracyclines:
Fluoroquinolones:
Pot. Sulfonamides:
Macrolides:
Lincosamides:
Phenicols:
Nitroimidazoles:
Beta-Lactams: cell wall synthesis inhibitors
Aminoglycosides: protein synthesis inhibitors at 30s
Tetracyclines: protein synthesis inhibitors at 30s
Fluoroquinolones: DNA gyrase inhibitors
Pot. Sulfonamides: Folic acid pathway inhibitors
Macrolides: protein synthesis inhibitors at 50s
Lincosamides: protein synthesis inhibitors at 50s
Phenicols: protein synthesis inhibitors at 50s
Nitroimidazoles: DNA synthesis inhibitors
What 4 antibiotic classes are TIME dependent?
- Beta-lactams (pen’s and ceph’s)*
- Potentiated sulfas
- Macrolides
- Lincosamides
What 4 antibiotic classes are CONCENTRATION dependent?
- Aminoglycosides*
- Fluoroquinolones*
- Tetracyclines
- Nitroimidazoles
Which 5 antibiotic classes are BACTERICIDAL?
- beta-lactams
- aminoglycosides
- fluoroquinolones
- pot. sulfas
- nitroimidazoles
which 4 antibiotic classes are BACTERIOSTATIC?
- tetracyclines
- macrolides
- lincosamides
- phenicols
Which antibiotic class would empirically cover giardia?
nitroimidazoles
Which antibiotic class covers gram negative aerobes (pseudomonas, brucella, campylobacter, lepto, actinobacillus, bordetella, E. coli) and staphs, but NOT streps or anaerobes?
Aminoglycosides
What is the spectrum for penicillins?
streps
anaerobes
what is the spectrum for cephalosporins?
streps
gram + anaerobes
gram negatives (better with higher generations; needs higher doses)
Which antibiotic class would be BEST for mannheimia or histophilus infections (gram negatives)?
Macrolides
These antibiotics also cover gram positives
T/F: a lincosamide is an appropriate choice for clostridial, actinomyces, or nocardia infection
true – lincosamides should cover gram positives and anaerobes. They are great for abscesses and prophylaxis prior to dental procedures
Which 4 antibiotic classes are considered “broad spectrum”?
- FQs (gram -, staphs, rickettsia, mycoplasma)
- Pot. sulfas (gram +, -, protozoa)
- Tetracyclines (gram +, -, anaerobes, rickettsia)
- Phenicols (gram + aerobes and anaerobes, mycoplasma, rickettsia)
What are the 2 major potential side effects of beta lactams?
mild GI signs
hypersensitivity
what are the 3 major potential adverse effects of aminoglycosides?
nephrotoxicity
ototoxicity
vestibular toxicity
Decrease toxicity and increase efficacy by dosing ONCE daily.
What are the major potential side effects of tetracyclines?
esophageal strictures in cats
if IV in horses, FATAL
skeletal and dental issues
what are the major potential side effects of FQs?
cartilage toxicity (young, heavier, active)
retinal toxicity (cats, enro>5 mg/kg)
bone marrow suppression and arrhythmogenesis (prado)
prohibited ELDU in food animals
T/F: FQs are prohibited for ELDU in food animals
true
What are the potential adverse side effects of pot. sulfas?
MANY in dogs – hypersensitivity, allergic rxns, cutaneous rxns, KCS, hypothyroidism, bone marrow suppression, urinary crystal formaton
safest in horses – some colitis risk
cats – slobbers
DECREASE risk of side effects if treat for <5 days.
What is the MOST severe adverse effect of macrolides and lincosamides in horses and rabbits?
FATAL diarrhea
What side effect can occur in foals prescribed macrolide antibiotics?
anhidrosis and hyperthermia
if combined with rifampin, also anemia and hepatotoxicity
T/F: a potential adverse side effect of lincosamide antibiotics in dogs is anorexia and vomiting
true
in cats – esophageal ulcers
why are phenicol antibiotics prohibited in food animals?
idiosyncratic irreversible aplastic anemia in ppl
what are the major adverse side effects of phenicol antibiotics?
hematologic toxicity - cats
non-palatible
florfenicol can cause dry eye
idiosyncratic aplastic anemia in ppl
what is the major potential side effect of nitroimidazoles?
neurotoxicity
T/F: nitroimidazoles are prohibited for ELDU in food animals
true
when is oral administration of antibiotics CONTRAINDICATED?
vomiting/diarrhea/GI disease
obstruction
anorexia
life-threatening illness
Though IM injections are tolerated well by patients and has reliable asborption, what is the downside to this administration route?
there is a risk of injection site reactions
when should you NOT choose SQ administration route?
dehydrated patients and horses (too large of volume)