Lecture 15: Pharmacology Flashcards
What results in resistant bacteria
inappropriate use of antibiotics and incorrectly prescribe antibiotics
what 3 antibiotics do you want to save for last resort
- Vancomycin
- Imipenem
- Chloramphenicol
what are reasons for antibiotic use
- Prevent infection-perioperative
- Tx established infection
- Prevent infection in predisposed patient
what should you consider when picking an antibiotic
- Penetration of drug to site of infection
- Severity of infection
- Compliance
what aids in antibiotics ability to penetrate tissue
- Lipid solubility
- Presence of inflammation in acute infection increase microvascularity
- Adequate blood supply
what are the major adverse drug reactions
- Colitis
- Nephrotoxicity
- Cartilage effects in growing animals
- Teratogenic effects
- IMHA
- Bone marrow suppression
- Cardiotoxicity
- Neuromuscular blockage
what is bacteriostatic
drug inhibits growth of agent may kill if high enough concentration reached
what is bacteriocidal
drug kills agent
what does it mean to be a time dependent antibiotic
to be effective need to be above MIC for over 50% of time, need to be dosed more frequently or given via CRI
what are some examples of time dependent antibiotics
beta-lactams and tetracyclines
what does it mean to be concentration dependent antibiotic
activity is best predicted by relationship between peak drug concentration and MIC of organism, dose infrequently
what are some examples of concentration dependent antibiotics
aminoglycosides, fluoroquinolones
what is an example of synergistic antibiotics
beta-lactam with aminoglycoside
what is an example of antagonistic antibiotics
chloramphenicol and gentamicin, penicillin and tetracyclines, chloramphenicol and erythromycin
what does broad spectrum target
gram negative and positives, +/- anaerobes
Are potentiated sulfas broad or narrow spectrum
broad
is metronidazole broad or narrow
narrow- only anaerobes
What is the MOA of aminoglycosides
inhibit protein synthesis by binding to ribosomal 30S subunit
describe the distribution of aminoglycosides
Distribute well extracellularly, do not penetrate CNS, eye or prostate
what is major adverse effect of aminoglycosides
nephrotoxicity
are aminoglycosides cidal or static
cidal
what is spectrum for aminoglycosides
gram negative aerobes
what aminoglycoside should be given to adults vs foals
adults: gentamicin
Foals: Amikacin
what is the MOA of penicillin
cell wall inhibitor
what is spectrum of penicillin
Excellent against gram positives, later generations have more gram negatives
what is distribution for penicillin
extracellular, do not distribute to CNS, eye or prostate
penicillins are static or cidal and time or concentration dependent
cidal and time dependent
which is a cheaper penicillin option: procaine or potassium penicillin
procaine penicillin
what is MOA of amino penicillin
cell wall inhibitor
what is spectrum for amino penicillin
greater gram negative spectrum
what do extended spectrum penicillins have greater activity against
gram negatives
what is MOA of cephalosporins
cell wall inhibitors
what is an example of 1st gen cephalosporin
cefazolin
what is example of second gen cephalosporin
Cefoxatin
What are some examples of third generation cephalosporins
ceftiofur sodium, ceftiofur crystalline, cefotaxime
what is an example of 4th gen cephalosporin
cefepime
as you go higher in cephalosporin generations they become more __spectrum and have better resistance to __
broad spectrum, beta lactamases
what is MOA of imipenem
cell wall inhibitor
what is spectrum for imipenem
gram negative
what condition in foals should you use imipenem
septic foals
what is MOA of potentiated sulfas
trimethorpim inhibits production of folate. Sulfazadine looks like PABA and gets mistaken for that in folic acid production pathway
what is spectrum for potentiated sulfas
Good broad spectrum aerobically, minimal anaerobic activity
Are potentiated sulfas cidal or static and time or concentration dependent
cidal and time dependent
what is MOA of fluoroquinolones
inhibits DNA gyrase and resulting in inhibition of
DNA coiling
what is distribution for fluoroquinolones
well to tissues and penetrates intracellularly
Are fluoroquinolones cidal or static
cidal
what is spectrum for fluoroquinolones
broad spectrum aerobically but not anaerobic action
what class do enrofloxacin and marbofloxacin belong to
fluoroquinolones
what is MOA of tetracyclines
inhibit protein synthesis by binding 30S ribosomal subunit
what is distribution for tetracyclines
well distributed, except CNS and eyes
what is spectrum for tetracyclines
broad spectrum aerobes, mycoplasma, rickettsia, some anaerobes
are Tetracyclines cidal or static and time or concentration dependent
static, time dependent
doxycycline, Oxytetracycline and minocycline are all part of what class
tetracyclines
what is MOA of macrolides
inhibit protein synthesis by binding 50S ribosomal subunit
what is distribution for macrolides
good for intracellular organisms
what spectrum are macrolides and what specific disease are they good at tx
gram positive and negative aerobes, mycobacteria, nocardia, cryptosporidium, Helicobacter, toxoplasma
Really good for rhodococcus
clarithromycin and azithromycin are from what class
macrolides
what is MOA of rifampin
inhibit RNA polymerase
what is distribution for rifampin
effective against intracellular organisms because of its lipid solubility and penetration of neutrophils and macrophages
is rifampin cidal or static
cidal
always use rifampin in concert with __ or __ since resistance develops quickly
SMZ, clarithromycin
what is MOA of chloramphenicol
inhibits protein synthesis by binding 50S ribosomal subunit
what is distribution for chloramphenicol
distributes most tissues, gets into abscesses
is chloramphenicol cidal or static
static, but at high does can be cidal
what is negative effect of chloramphenicol in humans
aplastic anemia
what is spectrum for chloramphenicol
broad spectrum of gram positive, negative, aerobes and anaerobes
what is MOA of metronidazole
disrupts bacterial DNA
what is distribution for metronidazole
excellent distribution including CNS and abscesses
is metronidazole cidal or static
cidal
what is spectrum for metronidazole
Protozoa and anaerobic bacteria, no effect against anaerobes
what abx is very good at tx B. Fragillis resistant to penicillin
metro
what is MOA of glycopeotides
inhibit cell wall synthesis and RNA synthesis
what is distribution of glycopeptides IV vs orally
widely distributed after IV but not into CSF, not orally bioavailable
are glycopeptides time or concentration dependent
time dependent
what is spectrum for glycopeptides
MRSA, enterococcus, C. Diff diarrhea
what class of abx is vancomycin
glycopeptide
how do NSAIDS work in COX pathway
reduce prostaglandins by inhibiting COX
COX1 is expressed where and has what effects
GI, kidney, platelet function
Homeostatic effects
COX-2 is expressed where and has what effects
all tissues, inflammatory effects
what are 3 non-selective COX inhibitors
banamine, bute, acetaminophen
what is an example of a COX-2 specific inhibitor
firocoxib
t or f: it is a great idea to stack NSAIDS
false
t or f: can you stack NSAIDS and steroids
only for short periods of time and monitor proteins closely
if your client is usually nutraceuticals what should it be certified by
NASC
what is a compounded drug
any drug manipulated to produce a dosage form drug
what is compounding allowed
have vet-client relationship and no other method or route of drug delivery is practical
t or f: compounding is evaluated by FDA for safety and efficacy
false
