inhibitors of protein synthesis

What are the Pharmacodynamics of macrolides?

Reversible binding to 50s ribosomal subunits (Transpeptidation and translocation, premature detachment)

What are methods of resistance to macrolides?

Efflux pump

rRNA

Methylation

Enzymatic inactivation of drugs

Gram ___ will be most susceptible to macrolides, newer macrolides can also hit Gram __ bacteria?

+, —

What are AE of all Macrolides?

IM - inj site pain

IV - thrombophlebitis

What are AE of Erythromycin (macrolide)?

Dose related GI (usually less)

Motilin agonist

C. diff - life threatening in horses

What are AE of Clarithromycin (macrolide)?

Fetotoxic

What are the Pharmacokinetics of Clarithromycin and Azithromycin (macrolides)?

High availability Long ½ life

Greater tissue concentration

- SID dosing

Macrolides are going to all be _____ in companion animals?

EXTRA LABEL

What are indications for azithromycin?

Susceptible bacterial infxns

Protozoal dz

Rhodococcus equi (combined w/ rifampin)

What are indications for Clarithromycin?

Bacterial

Leproid dz

Rhodococcus equi

Lawsonia intracellularis (EPE)

What are indications for Erythromycin?

Bacterial (susceptible)

What are the 5 macrolides used in livestock and not humans or companion animals?

Gamithromycin

Tildipirosin

Tilmicosin

Tulsthromycin

Tylvalosin

Of the macrolides used in livestock, which is the only NOT USED in cattle?

Tylvalosin - Swine, porcine proliferative enteropathy/

What are the Pharmacodynamics of lincosamides?

Reversible binding to 50s ribosomal subunits (protein inhibition)

What is Lincosamides spectrum?

Aerobic and

Anaerobic Gram +

Anaerobic Gram —

What are Methods of resistance to Lincosamides?

Methylation of 23s ribosomal subunit (part of 50s)

Adenylation of lincosamides

Efflux pumps

What are AE of Lincosamides?

GI disturbances (general and poss C. diff)
Peripheral neuromuscular blockade and

Cardiac muscle depression

What are Contraindications for lincosamides?

Pocket pets - toxic - cecocolitis

Not given w/ anestheticsWha

What are specific AE of Clindamycin (lincosamides)?

Cats - esophagitis/ strictures

Horses - pseudomembranous colitis (C. diff) fatal 

Lincosamides are not to be used in what animal?

Cattle

Lincosamides is indicated for what in swine?

Infectious arthritis

Mycoplasmal pneumonia

What are the pharmacodynamics of Phenicols?

Reversibly bind to 50s subunit (inhibits peptidyl transferase activity)

What are methods of resistance to Phenicols?

Acetylation of medications

Efflux pumps

50s acetylated

What is the spectrum of Phenicols?

Pretty much hits it all (G —/+, aerobic/anaerobic, atypical)

What are AE of Phenicols in dogs/cats?

Anemia

GI signs

Peripheral neuropathy

Why are AE of Phenicols worse in cats?

They need to be glucoronidated

Why is it not a good idea to send home Phenicols?

Can cause aplastic anemia in humans and need to be administered carefully/

AE of Florfenicol (Phenicol) are ___ in cattle?

Mild/uncommon (Diarrhea, reduced H2o intake, inj site rxns)

What are indications for Chloramephenicol (Phenicol)?

GI,

pulmonary 

UTI

Extra label for suspectible infxns (Big guns prob don’t do empirically).

Chloramphenicol is CI/banned in what animals?

Livestock

Florfenicol is labeled for what?

Resp dz in large animals (not horses)

What are pharmacodynamics of Tetracycline?

Reversible binding to 30s ribosomes (Prevents aminoacyl tRNA from attaching)

What types of bacteria are resistant to tetracyclines?

B. fragils,

Proteus

Pseudomonas

Bacteria use __ to resist tetracycline (the drug) but they can be _ to Doxy and minocyline?

Efflux pumps,  Susceptible

What are pharmacokinetics of tetracylinces?

ORAL, IM, SQ Chelate (combine w/ metals if given orally w/ food)

Deposits in bones and teeth

No BBB penetration.

What animal doesn’t tolerate tetracyclines well?

Cats - esophageal injury (esp doxy - give w. H20!!!)Wh

What are AE of Tetracyclines (7)?

GI

Reticuloruminal stasis

Inhibition of bone growth (don’t give to growing animals)

Teeth staining

liver damage & photosensitivity in light skinned (sun burns)

SUperinfections

Fanconi syndromes (Basenji)What

What is Fanconi syndrome?

Failure of PCT in kidney to reabsorb glucose, phosphate, and bicarb

Tetracyclines MUST be ___ after their expiration b/c there is a higher likelihood of Fanconi syndrome?

Disposed of

Tetracyclines are CI in what animals?

Growing - inhibits bone growth

Tetracycline, oxytetracycline, and doxycycline are labeled in what animals?

Dogs

Cats

Horses

Chlortetracycline is labeled in what?

Psittacine’s (Parrots)

What is an extra label tetracycline that can be used as an alternative to doxycycline of there is a shortage?

Minocycline

Why might we use tetracycline in livestock?

Resp dz

Bacterial enteritis

What is the only group of protein inhibitors that are bactericidal

Aminoglycosides

What are methods of resistance of Aminoglycosides?

irreversible inhibition of 30s ribosomal subunit

What are methods of Resistance to Aminoglycosides?

Mutations to 30s subunit

Enzymatic modification of drug

Decreased permeabillity

Drug efflux

What is the spectrum of aminoglycosides?

Aerobic Gram — enteric bacteria (NARROW - often combined w. other ABXs - NOT effective against Anaerobic species)

What are molecular pharmacokinetics of Aminoglycosides?

Polar and large 0require active transportation/ oxygen presents to enter bacterial cells.

Aminoglycosides are on a ____ ban in cattle?

Voluntary ban

What are indications of gentamicin in livestock?

Egg cleaning - turkeys

E. coli - swine

young animals

Gentamicin has a ___ withdraw time?

Long

What are indications for neomycin in livestock?

Bacterial enteritis

Mycoplasma synovia

P. multocida (fowl)

What are indications for Amikacin in companion animals?

IV admin for genitourinary infxns in Horses and Dogs.