Final Flashcards
What is the activity of ALL beta lactams?
bactericidal, time dependent, PAE
How are ALL beta lactams metabolized and excreted?
no metabolism, renal elimination
What two adverse effects are associated with beta lactams?
type A - GI toxicity
tybe B - allergies +++, cross reactivity
What are the two aminopenicillins?
amoxicillin and ampicillin
What are the two Beta lactamase resistant penicillins? (anti staphylococcal)
methicillin, oxacillin
What are the two extended spectrum penicillins?
ticarcillin, piperacillin
What group of beta lactams has a “eagle effect”?
penicillins
What is the difference in spectrum between basic penicillins and aminopenicillins?
aminos have more aerobic gram - spectrum (both do pasteurella)
What benefits are achieved by combining penicillins and aminoglycosides?
increased penetration of aminoglycosides inside bacteria, additive or synergistic effect
What can penicillin be degraded by? (3)
GI amidases and acidity (poor oral absorption)
bacterial Beta lactamases
What two penicillins have increased oral bioavailability?
aminopenicillins and penicillin V
What two drugs can increase the half life of penicillins?
procaine and benzathine
What group of penicillins should never be used empirically?
anti-pseudomonal penicillins (extended spectrum)
What are the 3 generations of cephalexin drugs we need to know?
1st - cephalexin
2nd - cefuroxime
3rd - ceftiofur, cefovecin
What are the spectrums for each gen of cephalosporins?
1st - Gram + aerobic and anaerobic and beta lactamase +, modest gram - (but not gr - beta lactamse +)
2nd - mmore gram - (decreased gr +)
3rd - even more gram - (decreased gr +)
What cephalosporin has a very long half life for dogs and cats?
cefovecin (convenia)
What are the adverse reactions of cephalosporins?
A - GI toxicity, nephrotoxicity
B - common, cross reactivity
What group of drugs are carbapaems and monobactams?
beta lactams
What is a carbapenem drug?
imipenem
What is a monobactam drug?
aztreonam
What is the spectrum of carbapenems?
gram + and -, aerobes, anaerobes, beta lactamse +
What is the spectrum of monobactams?
most gram - (some beta lactamase +)
NOT active against gram +
What are the three peptide antibiotics?
glycopeptides - vancomycin
polymyxin B
bacitracin
What is the activity of glycopeptides?
bactericidal
both time and concentration dependent
What is the spectrum of vancomycin?
only gram + aerobes and anaerobes
What is the route of administration of vancomycin? How is it metabolized?
IV
not metabolized, renal excretion
What is the MOA of polymyxin?
disrupts cell membrane and anti-endotoxin effect
What is the activity of polymyxin B?
bactericidal, concentration dependent
What is the spectrum of polymyxin B?
only Gram - aerobes and anerobes including pseudomonas
When should systemic use of polymyxin B be indicated?
low doses for endotoxin activity
What group is Streptomycin?
aminoglycoside
What group is erythromycin?
macrolide
What group is spiramycin?
macrolide
What group is tulathromycin?
macrolide
What group is tylosin and tilmicosin?
macrolide
What group is spectinomycin?
aminoglycoside
What group is neomycin and gentamicin?
aminoglycoside
What group is amikacin?
aminoglycoside
What does the MOA of aminoglycosides depend on?
oxygen (does not do anaerobes)
What is the activity of aminoglycosides?
bactericidal (only protein synthesis that is)
concentration dependent
PAE
What is the spectrum of aminoglycosides?
gram -, only in aerobic conditions
What can aminoglycosides be synergistic with? What is the exception?
any wall or membrane disruptor but chemically incompatible with penicillins
What is the preferred admin route of aminoglycosides? What is the exception?
parenteral (exception: neomycin)
What things can inactivate aminoglycosides?
inactivated by acids (stomach, pus, drugs) divalent cations (Mg, Ca)
What is the activity of tetracyclines?
bacteriostatic, time dependent
What can inactivate tetracyclines?
di and trivalent cations - Ca, Mg, Al, Fe
How are tetracyclines metabolized? What is the exception?
no metabolism, mixed liver and renal elimination.
Doxycycline = 100% eliminated by liver
What is the activity of macrolides?
bacteriostatic, time dependent, anti inflammatory, GI prokinetic
What is the spectrum of macrolides?
extra and intracellular bacteria
aerobic Gram +, mycoplasma (#1 option)
What can be antagonistic with macrolides?
other protein synthesis inhibitors
How are macrolides metabolized?
inactivated by CYP450
liver elimination
What macrolide can cause cardiotoxicity when used parenterally?
tilmicosin
What group is clindamycin and pirlimycin?
lincosamide
What is the activity of lincosamides?
time dependent and bacteriostatic
What is the spectrum of lincosamides?
extra and intracellular bacteria
mainly Gram +, aerobes and anaerobes
limited against gr -
How are lincosamides metabolized?
inactivated by CYP450, mixed elimination
What are the three adverse effects with lincosamides
GI upset
peripheral neuromuscular blockade
cardiac depression effect
What antibiotic group is known as the “penicillin alternative”?
lincosamides (gram + anaerobes like penicillins) and intracellular
What is the activity of phenicols?
bacteriostatic, time dependent
What is the spectrum of phenicols?
extra and intracellular
gram + and -
aerobes and anaerobes
(4 quadrants!)
How are phenicols metabolized?
metabolized by glucoronidation, inhibitor of drug metabolism, liver elimination
What are the two adverse rxns of chloramphenicol?
bone marrow toxicity, gi toxicity
What group of antibiotics is a DNA replication inhibitor?
quinolones
What group of antibiotics are DNA damaging agents?
nitroimidazoles
What are the four drugs that are fluoroquinolones?
enrofloxacin, ciprofloxacin, marbofloxacin, orbafloxacin (all are -floxacins)
What drug is the active metabolite of enrofloxacin?
ciprofloxacin
What is the activity of quinolones? What other drug group is similar in activitiy?
bactericidal, concentration dependent
aminoglycosides are also
What is the spectrum of fluoroquinolones?
extra and intracellular bacteria
most aerobic Gr -
inactive against anaerobes
How are fluoroquinolones absorbed?
well orally, but decreased by di and trivalent cations
How are fluoroquinolones metabolized?
little to no metabolism (exception: enrofloxacin)
mainly renal elimination
What are the five type A adverse reactions of fluoroquinolones? Are there any Type B?
phototoxicity, retinal degeneration, neurotoxicity, articular damage in growing animals, tendon/ligament toxicity
B - relatively common, cross reactivity
What are the clinical uses of the three dose ranges of fluoroquinolones?
low - bacteria is sensitive
middle - potentially resistant
high - immunocompromised, pseudomonas
What are the three nucleic acid disruptors?
fluoroquinolones, rifampin, metronidazole
What is the activity of rifampin?
bactericidal, concentration dependent
What is the spectrum of rifampin?
extra and intracellular
most aerobic gram +
variable for gram -
obligate anaerobes are resistant
How is rifampin metabolized?
liver deacytylation, P450 and PGP inducer, liver elimination
What are the three adverse rxns of rifampin?
hepatotoxicity, bone marrow toxicity, teratogenecity
Which drug undergoes bioactivation in anaerobic conditions?
metronidazole
What is the activity of metronidazole?
bactericidal, time or conc dependent
only active in anaerobic conditions
What is the spectrum of metronidazole?
extra and intracellular most anaerobes (aerobes when in anaerobic environment) Gram - and gram +
How is metronidazole metabolized?
liver, mixed hepatic and renal elimination
What are the 3 adverse rxns of metronidazole?
gi toxicity, neurotoxicity (reversible), carcinogenic/teratogenic
What can be used to improve palatability of metronidazole?
ester benzoate compounded formulations - but off label use
What are the three metabolism inhibitor drugs?
sulfonamides, diaminopyrimidines, nitrofurans
What is the activity of sulfonamides and diaminopyramidines?
bacteriostatic, time dependent
What can decrease sulfonamide activity?
pus and necrotic tissues
What is the spectrum of sulfonamides?
extracellular
gr + and -
NOT active against anaerobes
some protozoa
How are sulfonamides metabolized?
liver, mixed liver and renal elimination
What are the three Type A reactions associated with sulfonamides?
thyroid inhibition, KCS, and nephrotoxicity
What group of drugs are trimethoprim and ormetoprim?
diaminopyramidines
What is the difference in spectrum of sulfonamides and diaminopyramidines?
diaminos can go intracellular
How are diaminopyramidines metabolized?
liver, eliminated in liver
What is the type A reaction associated with diaminopyramidines?
folate deficiency –> blood cytopenia
What are the three potentiated sulfonamides combinations?
Sulfamethoxazole - trimepthoprim
sulfadiazine - trimepthoprim
sulfadimethoxine - ormetoprim
What is the spectrum of nitrofurans?
extracellular gr + and - aerobes and anaerobes, and protozoa
How is nitrofuran eliminated?
liver metabolism (bioactivation to active drug) then very rapid renal elimination
What are the three choices of drug for mycoplasma?
- macrolides
- tetracyclinse
- phenicols
What three drug groups have an anti-inflammatory effect?
tetras, macrolides, fluoroquinolones
What 5 drugs cause GI toxicity?
o Beta lactams o Tetracyclines o Macrolides o Phenicols o metronidazole
What drugs should not be used first line or empirically?
o Cephalosporins o Monobactams o Imipenems o Extended spectrum penicillins o Vancomycin o Fluoroquinolones o nitrofurans
What drugs are nephrotoxic?
o Cephalosporins o Vancomycin o Polymyxin B o Bacitracin o Aminoglycosides o Sulfonamides
What drugs are cardiotoxic?
o Tilmicosin (macrolide) o Lincosamides
What drugs are neurotoxic?
o Polymyxin B
o Lincosamides
o Fluoroquinolones
o metronidazole
What drug groups do mostly gram +?
Older penicillins Macrolides Glycopeptides (vancomycin) Bacitracin rifampin
What drug groups do mostly Gr - ?
Aminoglycosides
Fluoroquinolones
Polymyxin B
What drug strictly only does anaerobes?
metronidazole
What three drug groups are concentration dependent?
Polymyxin B
Aminoglycosides
Nucleic acid disruptors (except metronidazole = both)
What drug groups are bacteriostatic?
Tetracyclines Macrolides Lincosamides Phenicols Sulfonamides Diaminopyramidines
What drug can be bacteriostatic or bacteriocidal depending on the bacteria?
nitrofurans
What two drugs are both time and concetration dependent?
vancomycin and metronidazole
What two drug groups have PAE?
beta lactams and aminoglycosides
What three drug groups are inactivated by acid?
o Penicillins
o Aminoglycosides
o Macrolides
What 5 drug groups do intracellular bacteria?
o Tetracyclines o Macrolides o Lincosamides o Phenicols o Fluoroquinolones o diaminopyramidines
What are the legal restrictions for antibiotics in FA?
o Vancomycin
o Voluntary against aminoglycoside extralabel use
o Chloramphenicol
o rifampin
o Florfenicol – labeled use for FA
o Fluoroquinolones – labeled use only for FA
o Metronidazole
o No extra label use in lactating dairy cattle
o nitrofurans
What three drug groups have good extracellular distribution?
beta lactams, sulfonamides, aminoglycosides
What drug groups have good CNS distribution even without inflammation?
sulfonamides diaminopyrimidines metronidazole rifampin chloramphenicol
What drug groups have deep tissue distribution?
diaminos, polymyxin, tetras, macrolides, lincosamides, fluoroquinolones, metronidazole
What 6 drug groups get excreted renally unchanged?
Blactams, glycopeptides, polymyxin, aminoglycosides, fluoroquinolones, nitrofurantoin, tetracyclines
What 5 drug groups can lose efficacy locally because of pus or aerobic/anaerobic conditions?
penicillins = pus, acidity, eagle effect
fluoroquinolones, tetracyclines, - cations, excess local
sulfonamides, - PABA analog rich environment
aminoglycosides, - anaerobic
metronidazole - aerobic
What two drug groups are P450 inhibitors/substrates?
macrolides and chloramphencol
What drug is a P450 inducer and PGP inducer?
rifampin