Antimicrobials 3 Flashcards
MOA of cephalosporins?
they are beta lactams, they bind to penicillin binding proteins (PBPs) and inhibit peptidoglycan cross linking
cephalosporins have a similar spectrum of action to _____
aminopenicilins
have some activity against beta lactamase producing strains and against some gram -s, but not very good for anaerobes
list some PD and PK characteristics of cephalosporins
- bactericidal (less so than penicillins)
- time dependent
- freuent administrations
- excretion in urine (good for UTIs)
- few adverse effects
name two practical uses of cephalosporin drugs
- prophylaxsis before surgery
- skin infections, staph
what are the two first class cephalosporins I need to know
cephalexin (more common, oral admin), cefazolin (injectable)
name clinical uses for cephalexin and cefazolin
cephalexin: staph pyoderma in dogs
cefazolin: periopperative prophylaxsis
what are the two third gen cephalosporins i have to know?
ceftiofur and cefovecin
third generation cephalosporins have greater activity against _____ pathogens than earlier generations
gram neg
what kind of drug is ceftiofur and what is it commonly used for in vet med?
a 3rd gen cephalosporin, commonly used in horses and production animals, UTIs in dogs
cefitofur sodium is short acting, ceftiofur crystalline free acid is long acting
what kind of drug is cefovecin, what is the brand name, and what is it used for commonly?
- a 3rd gen cephalosporin, very long acting and highly protein bound
- can be used for many many things, but DO NOT reach for it simply because of convienence
MOA of tetracylines?
they are protein synthesis inhibitors, interferes with binding of tRNA to the ribosome, inhibiting bacterial protein synthesis
list some PD and PK characteristics of tetracyclines
- bacteriostatic
- time dependent
- lipophilic (doxy moreso than oxy)
- quite variable in administration and excretion
tatracyclines are good for what bacteria?
anything except for gram - aerobes like E coli
what happens if you give tetracylines too fast IV?
hypotension and collapse, SO GIVE IT SLOWLY!!!
what are the two big tatracyclines I need to remember?
doxycycline (companion animals) and oxytetracycline (production animals)
list some clinical uses of oxytetracycline
- pneumonia and metritis in cattle/sheep/goats
- can be used for BRD in cattle
- potomac horse fever
- treat tendon contracture?
you have a horse with potomac horse fever. what drug are you going to give and how will you give it?
oxytatracycline, given IV but diluted in a fluid bag to avoid CV effects
what is some practical reasons to use doxycycline?
- for tick borne infections
- for mycoplasma
- chlamydia & resp infections
the oral form of doxycycline can cause _____ in cats. For this reason, if you give it to a cat, you should…
esophageal strictures
do not give it dry, give water or food afterwards!
which antimicrobial can be used as an add on treatment for heartworm in dogs? how does this work?
doxycycline. it kills the wolbachia organism in the worms, which helps the worms survive, so it makes the worms easier to kill
not only does doxycycline have an antimicrobial effect, but it also has a _____
anti inflammatory effect!
MOA of nitroimidazoles? what is the one drug in this class to remember?
produce short lived intermediates/free radicals inside bacteria/protozoans that damage their DNA
metronidazole
list some general characteristics for metronidazole. what is it good at killing?
- bactericidal, concentration dependent
- kills anaerobes and protozoans
which antimicrobial can be used to treat giardia in dogs?
metronidazole
Why should you not use metronidazole in production animals?
it is potentially carcinogenic and teratogenic
