bind to 30s ribosomes

prevent tRNA/mRNA binding

Gram + = energy dependent uptake

Gram - = diffusion into cell

slow/stepwise, cross resistance

plasmid mediated and inducible

alter gut flora and favor resistant bacteria

widespread use

broad spectrum and anaerobic coverage

bacteristatic

can use empirically for anaerobe infection

do not use in food animals

plasmid and multiresistant factors

R plasmids produce 3 types of CHLP acetytransferases

transfer resistance between E coli and susceptible salmonellas

broad spectrum, no anaerobe coverage (unless w/ ofloxacin)

combine with fluorine to increase gram - and pseudomonal effects

treat pseudomonal and staph int. dermatitis

none

no problems with gut/oral flora

inhibits DNA gyrase

superhelical DNA degrades

bactericidal

no plasmids

decreased DNA gyrase affinity or wall permeability

erode articular cartilage in horses and young

renal/urinary crystals

alters blood chemistry

basic (7.6)

high lipid solubility

well absorbed/wide tissue distribution

increase absorption, decrease irritation

stearate, ethylsuccinate, estolate

16 carbon members

toxic to horses

low resistance

can treat intracellular pasteurella, haemophilus, mycoplasma

give macrolides as second choice in penicillin G allergy

also in place of penicillinase-resistance penicillins

do not use macs/lincs

cause diarrhea and death (growth of C. dificile)

"pseudomembranous colitis"

treat with vancomycin and metronidazole

lincosamides treat dermatits and osteomyelitis (staph)

treat penicillin-resistant staph

not good choice for gram - bacilli

can treat actinobacillus, brucella, lepto, campylo, haemophilus, pasteurella, bordatella

chromosomal is stepwise/unstable

plasmid is stable, more common

methylate adenine residue in rRNA

*inducible - organisms sensitive to clindamycin can be induced to be resistant with exposure to erythromycin

cross resistance not seen with tylosin

narrow spectrum

active against gram + cocci but not staph

hydrolyzed by penicillinase

penicillinase resistant, active against staph

include methicillin, oxacillin, cloxacillin, dicloxacillin

ampicillin, amoxicillin

active against gram - and +

hetacillin converted to ampicillin intramammary

active against proteus, klebsiella

carbenicillin (indamyl), ticarcillin, mezlocillin, piperacillin

clavulanic acid = weak antibacterial and B-lactamase inhibitor

pair with amoxicillin, ampicillin, and others

effective against anaerobes, streptococci

B. fragilis = clavamox, azlo, piper, mezclo, carb, ticarb

orally active

broad spectrum

anaerobic coverage

B-lactamase resistant

penetrate body compartments (CNS)

treat with cefotoxitin

cephalosporin

treat pseudomonas

orally active

active against gram + and -

no antipseudomonal activity

very polar

low PO absorption/tissue distribution

need aerobic conditions for activity

enzymes modify -OH or -NH2 group 

alter ribosome binding

enzymes (different types) located in periplasmic space

spectrum based on enzyme resistance

high levels of resistance

don't use in renal disease

combine with B-lactam (ceftazidime, ceftriaxone) for pseudomonas

aerobic, gram - bacilli

not effective against anaerobes

use against staph aureus and epidermidis (second choice)

can treat pseudomonas (combine amikacin with ceftazidine, ceftriaxone)

don't use in renal patients - cause ATN (nonoliguric)

decreased GFR

avoid furosemide, control vomiting, use dialysis

use in serious/resistant infections

avoid hypokalemia

lincosamides

anti-staph penicillins

potentiated penicillins

orally active cephalosporins

aminoglycosides

fluoroquinolones

sulfa/TMP

extended-spectrum penicillins

anti-pseudomonal cephalosporins

animoglycosides

fluoroquinolones

lincosamides

penicillins

cephalosporins

chloramphenicol

metronidazole

3rd generation cephalosporins resistant to B-lactamase

broad-spectrum penicillins sensitive to B-lactamase

macrolide (inhibit bact protein synth in ribosome)

high intracellular drug concentrations

better bioavailability than erythtromycin

broad spectrum, good PO absorption

effective against macrolide resistant bacteria

short half-life

use in MRSA, vancomycin-resistant enterococcus

subunit substitution decreases 50S subunit affinity

cephadroxil

cephalexin

cephalothin

cephapirin

don't treat pseudomonas

ceftriaxone

ceftiofur

treat enterobacteriaceae

ceftazidime

treat pseudomonas

cefoxitin

cefotetan

treat bacteroides fragilis

cefoxitin

cefotetan

staph/strep/entero

anaerobes

osteomyelitis

abdominal infection

CNS infection

UTI

mastitis

R. equi

staphylococcus

e. coli

haemophilus

klebsiella

proteus

pseudomonas

salmonella

plasmid - against penicillin and cephalosporins

chromosomal - usually against cephs, or can be pen

clavulanic acid ineffective chromosomally-mediated cephalosporinases

sensitive to anaerobic conditions

low pH

hyperosmolarity

less activity in abscesses and hyperosmolar urine

4-8ug - gentimycin, tobramycin, netilmicin

8-16ug - amikacin, kanamycin

inactivation by bacterial enzymes (amikacin less susceptible)

cross resistance within group

chromosomal mutation (single step high level resistance)

aminoglycoside nephrotoxicity

(factors that exacerbate it)

neomycin

paralysis and apnea during anesthesia

calcium gluconate 10% solution

reversible anticholinesterase (neostigmine)

chemical combo with B-lactams

synergize with ceftazidine

toxicity increase with furosemide

amikacin + ceftazidime/ceftriaxone = dead pseudomonas

once daily

significant post-antibiotic effect

small MCB/MIC ratio

bactericidal

concentration dependent killing and PAE

first exposure effect

less accumulation

Acute renal failure

1. decreased urine concentrating ability

2. proximal tubular cell death with casts in urine

3. reduce GFR, serum creat and BUN elevation

4. regeneration

hypokalemia

hypercalcemia

hyperphosphatemia