ABX-Buckley Flashcards
Penicillins
Ampicillin
Amoxicillin
Pen G
Penicillins MOA, classification
- MOA: bind to penicillin binding proteins to disrupt cell wall synthesis
- bactericidal, time dependent
Penicillins spectrum
- mainly gram positive, some activity against gram negatives but not reliable
- active against most anaerobes except bacteroides
- little activity against pseudomonas
Cephalosporins
1st gen: cefazolin, cephalexin
2nd gen: cefoxitin, cefuroxamine
3rd gen: cefotaxime, ceftiofur, ceftriaxone, cefpodoxime, ceftazidime
Cephalosporins MOA, classification
- MOA:inhibit cell wall synthesis
- bactericidal, time dependent
Cephalosporins spectrum
As you go from 1st to 3rd generation, the spectrum changes from gram positive (g1) to mainly gram negative (g3)
Lincosamides
clindamycin
Lincosamides MOA, classification
- MOA: prevent protein synthesis by binding to 50S ribosome
- bacteriostatic, time dependent
Lincosamide spectrum
- clindamycin (only lincosamide taught in this course) has good activity against gram positive aerobes including MRSA and against anaerobes
- resistance is about 50% in Bacteroides spp.
- they have little efficacy against gram negative organisms.
Potentiated Penicillins
ampicillin-sulbactam (unasyn), amoxicillin-clavulanate (clavamox)
Potentiated Penicillins MOA, classification
- MOA: inhibit cell wall synthesis
- bactericidal, time dependent
Potentiated Penicillins spectrum
- good activity against gram positive organism, improved activity against gram negative bacteria as compared to regular penicillins
- improved activity against Bacteroides spp. (90% effective)
Fluoroquinolones
enrofloxacin (baytril), marbofloxacin, ciprofloxacin
Fluoroquinolones MOA, classification
- MOA: bind to DNA gyrase and topisomerase IV to prevent gene transcription
- bactericidal, concentration dependent
Fluoroquinolones spectrum
- good activity against gram negative organisms, poor activity against gram positives or anaerobes
- high doses can be used for Pseudomonus spp.
- toxic to cats at high doses (>5mg/kg = retinal degeneration)
new fluoroquinolone
pradofloxacin
- not reported as being toxic in cats
- broader spectrum of action, gram positive and some anaerobes
- not labeled for use in dogs
Aminoglycosides
amikacin, gentamycin
Aminoglycosides MOA, classification
- MOA: bind to 30S ribosome and prevent protein synthesis
- bactericidal, concentration dependent
Aminoglycosides spectrum
- excellent activity against gram negative organisms including resistant E. coli
- can be synergistic with penicillins in the treatment of some gram positive infections such as enterococcus, MRSA
- nephrotoxic!!
Tetracyclines
Doxycycline, minocycline, tetracycline, oxytetracycline
Tetracyclines MOA, classification
- MOA: bind to 30S ribosome to inhibit protein synthesis
- bactericidal
Tetracyclines spectrum
- excellent penetration to lung
- good spectrum against gram positive bacteria, tick borne pathogens, Leptospira and Mycoplasma spp.
Carbapenems
Imipenem, meropenem
Carbapenems MOA, classification
- MOA: inhibit cell wall synthesis
- bactericidal, time dependent
Carbapenems spectrum
- excellent broad spectrum activity (gram positive, gram negative, and anaerobes
- no activity against MRSA, limited against MDR enterococcus
- expensive, injectable only
- last resort drug
Metronidazole MOA, classification
- MOA: causes DNA strand breaks
- time dependent
Metronidazole spectrum
- excellent activity against anaerobes and protozoa
- at high doses it is associated with development of vestibular signs (d/c drug, CS disappear in a few days)
Chloramphenicol MOA, classification
- MOA: binds to 50S ribosome
- bacteriostatic
Chloramphenicol spectrum
- gram positive and gram negative
- good for MDR Enterococcus spp. and E. coli
- risk of irreversible bone marrow suppression in humans
- take care
