What are antibiotics
drugs that suppress bacteria
What does bacteriocidal mean
drug that KILLS the bacterium
What does bacteriostatic mean
drug that inhibits bacterial repduction
what are beta lactams (2)
Penicillins
Cephalosporins
MOA of beta lactams
inhibit cell wall synthesis
Penicillins work on/how?
Bacteriocidal
G+, aerobic, +/-anaerobes
What does the addition of clavulanic acid do for beta lactams
lactamase protector - helps with bacteria that developed Beta-lactamase.
Allows coverage of G- too
What do newer generations of penicillin provide
extended spectrum of activity - more anaerobes and G-
ONLY IV - ticarcillin, carbenicillin, methicillin, imipenem
Penicillin side effects
Rare - V/D, allergic rxn
Cephalosporines work on/how?
Bacteriocidal
Broad spectrum - more resistant to B-lactamases
What do newer generations of cephalosporines provide
more G- bacteria coverage
1st - cephalexin; 2nd - cefotetan; 3rd ceftiofur; 4th - cefquinome
Cephalosporines side effects
V/D, allergic rxn
Aminoglycoside MOA
Inhibit protein synthesis - 30s ribosome
Aminoglycosides work on who/how?
Both cidal and static
G- (+), aerobes and some facultative anaerobes
Aminoglycoside examples
gentamycin, amikacin
Aminoglycoside side effects
Nephrotoxicity, Ototoxicity (if tympanic rupture)
Polymyxin MOA
Cytoplasmic membrane structure
Polymxyin applied how?
topically only!
Polymyxin side effects
Pemphigus vulgaris - skin immune-mediated disease
Chloramphenicol work on who/how?
Static
broad spectrum
Chloramphenicol MOA
Protein synthesis (50s)
Tettracyclins MOA
Doxycylin, oxytetracylin, minicyclin
Tetracyclins work on who/how?
Static
aerobic and anaerobic G+/-
mycobacteria, spirochetes, mycoplasma, rickettsiae, chlamydiae, protozoa
Tettracyclins MOA
Protein synthesis (30s) Doxycylin, oxytetracylin, minicyclin
Macrolides and Lincosamide MOA
erythromycin, clindamycin
Macrolide and Lincosamide work on who/how?
Cidal
G+ and rickettsiae
Macrolides and Lincosamide MOA
Protein synthesis (50s) erythromycin, clindamycin
Macrolide and lincosamide side effects
few - V/D, nausea, pseudomembranous colitis
Nitroimidazoles MOA
metronidazole/ronidazole
Nitroimidazole work on who/how?
uptaken by bacteria - produce toxic metabolites
Anaerobic bacteria and protozoa
metronidazole/ronidazole
Nitrofurans MOA
rapidly absorbed and excreted in urine - used for urinary infections
Nitrofurans MOA
Protein synthesis (30s) rapidly absorbed and excreted in urine - used for urinary infections
Nitrofurans side effects
nausea, vomiting
Sulphonamides MOA
ineffective in pus, nectroic tissue or blood containing PABA
Sulphonamides MOA
Inhibit PABA conversion (folic acid)
ineffective in pus, nectroic tissue or blood containing PABA
Sulphonamide side effects
common, hepatic dz, renal dz/uroliths, keratoconjunctivitis sicca, hypersensitivies
ETC.
Quinolones MOA
excreted in bile - good for liver infections
enrofloxacin, ciproflaxacnin
Quinolones MOA
DNA gyrase
excreted in bile - good for liver infections
enrofloxacin, ciproflaxacnin
Quinolones side effects
CNS (seizure, retinal blindness (cats)), cartilage damage in puppies