Equine Pharmacology

Name 3 antibiotics we try to save for human usage only, only use as a very last resort?

Vancomycin

impenem

Chloramphenicol

Why do we use abx?

Prevent infection preoperatively

Prevent secondary infection

Treatment of an established infection

What are considerations when picking an abx?

Penetration of drug at the sight

Severity of infection

Compliance (ability to give meds)

What are the main concerning AE of ABX in horses?

Colitis

Nephrotox

Cartilage effects in growing animals

Teratogenic effects

IMHA

A bacteriostatic will ____ bacteria. A bacteriocidal ABX will ____ bacteria?

Inhibit growth

Kill

What is a time dependent ABX?

efficacy of the abx is correlated with the length of time above the MIC - More frequent dosage

What is concentration dependent ABX?

achieve increasing bacterial kill with increase the dose of drug - Give large dosages less frequently

What is an example of synergistic abx usage?

B-lactams + aminoglycosides

What is an example of antagonistic abx usage?

Chloremphenicol and gentamicin

What spectrum of ABX should we use for empirical tx?

Broad spectrum

What is the MOA of Aminoglycosides?

Bind 30s subunit and interfere with protein translation - Via oxygen dependent interactions w/ LPS in Gram - bacteria

What is the distribution of Aminoglycosides?

Extracellularly - no Immune privileged site penetration

What is the spectrum of aminoglycosides?

Bactericidal - gram neg aerobes

Aminoglycosides have a ____ killing?

Dose dependent - long post abx effect

Name 2 aminoglycosides used in equine?

Gentamicin - adults

Amikacin - Foals

What is the MOA of all beta lactase?

Bind to penicillin binding proteins - prevent cell wall synthesis

What is penicillins spectrum?

Gram +

What is the distribution of penicillins?

Extracellular - renal excretion - no immune privilege penetration

All B-lactams will have _____ dependent bactericidal effects?

Time

How are aminopenicillins different from penicillins?

Get more gram - bacteria

What is an example of an amino penicillin?

Ampicillin

What allows fro extended spectrum penicillins to get more gram - bacteria?

Large polar groups on side chains

What is an example of an extended spectrum penicillin?

Ticarcillin

Name a first gen cephalosporin?

Cefazolin - good for eye tx

Name a second gen cephalosporin?

Cefoxatin

Name two third gen cephalosporins?

Ceftiofur

Cefitiofur crystalline free acid - 4 day IM inj

Which beta-lactam inhibitor has a gram- effect that we save for emergencies/ human med?

Imipenem

What is the MOA of Potentiated sulfas?

Trimethoprim - Inhibits dihydrofolate reductase - decreases folate

Sulfadiazine - Competes w/ PABA to inhibit folic acid production

What is the spectrum of Potentiated sulfas?

Broad spectrum - aerobically - gets into most tissues

Potentiated sulfas are ____ dependent and bacteri___?

Time

Cidal

What is the MOA of floroquinolones?

inhibit DNA gyrase (prevents supercoils)

What is the distribution of floroquinolones?

Penetrates intracellularly

-kidney elim

Floroquinolones are Bacteri____ drugs w/ a ____ dependent effect?

Cidal

Dose dependent - post abx effect

What is the spectrum of fluoroquinolones?

No anaerobic action

What are two fluoroquinolones used in equine med?

Enrofloxacin

Marbofloxacin

What is the MOA of tetracyclines?

Inhibits 30s

What is the distribution of tetracycline?

No CNS or Eyes

What is the spectrum of Tetracyclines?

Broad spectrum aerobically - mycoplasma, ricketsia

Tetracyclines are Bacteri____ and have ____ dependent effects?

Static

Time

What is the MOA of Macrolides?

Inhibits 50s

What is the distribution of Macrolides?

Widely distributed in most tissues

What is the main usage of macrolides in equine med?

Rhodococcus / Intracellular organisms

Macrolides are bacteri____?

Static

Name two macrolides?

Clarithromycin

Azithromycin

What is the MOA of rifampin?

Inhibits RNA polymerase

What is the distribution of rifampin?

Gets into abscesses well

Rifampin is Bacteri___ but needs to be?

Cidal

Needs to be combined -resistance formed quickly

What is the MOA of Chloramphenicol?

50s inhibition

What is the spectrum of chloramphenicol?

Broad spectrum - aerobic and anaerobic - can get into abscesses

What is a major AE of chloramphenicol?

Aplastic anemia - O can get as well

Chloramphenicol is a bacteri___ drug?

Cidal

Metronidazole is a bacteri___ drug?

Cidal

What is the MOA of Metro?

Nitro reductase - toxic intermediates disrupt bacterial DNA

What is metronidazole's spectrum?

Protozoa

Anaerobic bacteria

Bactericides fragillis - pen resistance

What is the MOA of glycopeptides?

Inhibits cell wall synthesis and RNA synthesis

What is the distribution of Glycopeptides?

No CSF

Dont give oral

Glycopeptides are ____ dependent?

Time

What is the spectrum of glycopeptides?

MRSA

Enterococcus

Clostridial difficile

Name a glycopeptide?

Vancomycin - save for human use

What is the legal definition of hemp?

0.3% or less THC

Based on the research what might we use CBD for?

Reduction of inflammation? more to come?

Which COX receptors will be normal physiologic functions and not inflammatory?

Cox 1

Name 3 nonselective cox inhibitors

Flunixin meglumine

Phenylbutazone

Acetaminophen

Name the a cox 2 specific inhibitor

Firocoxib - low pain

What is compounding?

Any drug manipulated - only do if no FDA product available or if prep can't be made from FDA approved drug

When is compounding allowed?

Unable to deliver in usual form

Valid vet-client-patient partnership

Compounding drugs to mimic licensed FDA drugs is considered ___?

Illegal