Antibiotics #2 Flashcards
Antibiotics within the same structural class will generally show _______ pattern of effectiveness, ______ and _____-potential side effects.
similar, toxicity, allergic
Name the drug classes that are inhibitors of cell wall biosynthesis.
Beta-lactam penicillins:
➢ Cephalosporins
➢ Carbapebems
➢ Monobactam
Name the drugs that are inhibitors of protein synthesis.
➢ Aminoglycosides
➢ Tetracyclines
➢ Phenicol Group
➢ Macrolides
➢ Lincosamides
Cephalosporins are employed for ?
antibiotic prophylaxis
First alternative to penicillins (penicillin-intolerant patients)
What is the MOA of Cephalosporins?
inhibition of cell wall synthesis: via binding PBPs and interfering
with peptidoglycan synthesis
What is the route of Cephalosporins?
most given parenterally
Why is there resistance to Cephalosporin?
Due to bacterial β-lactamase production
What are the adverse effects of Cephalosporin?
Rare. Cephalosporins are considered to be among the safest antimicrobials in use
MRSA infections are __________-resistant Staphylococcus _________ infection (superbug).
Potentially dangerous type, can cause ______ in human
methicillin, Aureus, sepsis
MRSA infections are not common in ____ and ____.
What are these species more likely to be infected with?
dogs, cats
Dogs are more likely to be affected by a different bacterial strain called methicillin-resistant Staphylococcus
Pseudintermedius or MRSP. These infections usually infect dogs through skin
wounds, surgical sites and ears
Why are we concerned about MRSA?
MRSA is emerging concern in Vet Med. The true scope of MRSA in animals and its
impact on human health are still only superficially understood, but it is clear that MRSA
is a potentially important veterinary and public health concern that requires a great
deal more study to enhance understanding and effective response
- What are the therapeutic uses of:
Cephalexin
Cephalothin - Used in what species?
Employed for antibiotic prophylaxis. Treat penicillin-intolerant patient
All species
- What are the therapeutic uses of:
Ceftiofur - Used in what species?
- respiratory disease
cattle mastitis
UTI and soft tissue infections - Cattle, horses, sheep, pigs, dogs, cats
What are the therapeutic uses of:
Cefoperazone
2. Used in what species?
- soft tissue infections
Gram (-) bacteremia - Dogs
What are the therapeutic uses of:
Cefotaxime
2. Used in what species?
- Gram (-) sepsis
soft tissue infections
meningitis, CNS infectio - Dogs, cats, horses
What are the therapeutic uses of:
Cefpodoxime
2. Used in what species?
- skin infections
- Dogs, cats
What are the therapeutic uses of:
Cefixime
2. Used in what species?
- UTI, respiratory infections
Bacterial endocarditi - Dogs, cats; bact = just dogs
What is the function of Carbapenems?
Bind to penicillin binding proteins (PBPs)
List the Carbapenems and their broad spectrum of action.
What are the therapeutic uses of Carbapenems?
Very serious infections such as
peritonitis
What is the route of administration of Carbapenems?
IV
Resistance to Carbapenems is due to?
β-lactamases (carbapenemases) can cleave all types of β-lactams
What are the adverse effects of Carbapenems?
▪ Anorexia, vomiting , diarrhea
▪ CNS toxicity (seizures, tremors)
▪ Pruritis, fever
▪ Anaphylaxis (rare)
List the Monobactams and their broad spectrum of action.
Bind to penicillin binding proteins (PBPs)
Aztreonem
What is the route of administration of Monbactams?
parenterally
Resistance to Monobactams?
it is stable to most β-lactamase
What are the adverse effects of Monobactams?
Hypersensitivity reactions
List the inhibitors of protein biosynthesis.
Aminoglycosides, tetracyclines, phenicol group, macrolides, lincosamides
What is the MOA of inhibitors of biosynthesis?
Targeting 2 different ribosomal subunits.
Prokaryotic = 16S?
Eukaryotic = 17S?
Bacterium = 70S (different calc here which is why it ids 80 total, but it is correct)
30S subunit —> Impairing proofreading ability, blocking association with rRNA
50S subunit —> blocking peptide bond formation bet. Amino acids
List the drug class that targets 30 S ribosomal subunit
Aminoglycosides
Tetracyclines
List the drugs that target 30S ribosomal subunits
Streptomycin
Doxycycline
List the drug classes that target the 50S ribosomal subunit
Chloramphenicol
Macrolides
Lincosamides
List the drugs that target the 50S ribosomal subunit
Chloramphenicol
Lincomycin
Erythromycin
List the aminoglycosides that target the 30S ribosomal subunit
Aminoglycosides (bactericidal)
Streptomycin Gentamicin Neomycin Kanamycin Plazomicin
List the tetracyclines that target the 30S ribosomal subunit
Tetracycline
Doxycycline
List the Chloramphenicols that target the 50S ribosomal subunit
Chloramphenicol (bacteriostatic) ❑ Florfenicol (bactericidal)
List the Macrolides that target the 50S ribosomal subunit.
Macrolides (bacteriostatic)
Erythromycin Azithromycin Tylosin
List the Lincosamides that target the 50S ribosomal subunit
Lincosamides (bacteriostatic)
Lincomycin Clindamycin Pirlimycin
What is the function of aminoglycosides?
Aminoglycosides (bactericidal)
Irreversibly bind to the 30S ribosome and inhibit the rate of protein synthesis and the fidelity of mRNA translation resulting in the synthesis of abnormal proteins
What is the function of tetracyclines?
Tetracyclines (bacteriostatic)
Reversibly bind to 30S ribosome and prevent the attachment of tRNA to the mRNA-complex resulting in blocking
of the growing peptide chain
What is the therapeutic uses of Streptomycin?
What species is it used in?
Is it Gram - or Gram +?
Is it an aerobe or anaerobe?
The oldest member, it’s use is declined
All species
Gram -
Aerobe
What are the therapeutic uses of Gentamicin, Amikacin?
Is it Gram - or Gram +?
Write q from before4
Expanded spectrum: Gram (+) Control of infections of the uterus skin, respiratory, UTI, ear, eye, septicemia
Horses, dogs, cats
Neomycin
Enteric infections (orally)
skin, ear and eye infections (topical)
Pigs, sheep, dogs, cats
Kanamycin
Bacterial enteritis (orally) symptomatic relief of the diarrhea
Dogs
Plazomicin
Next generation, without nephrotoxic and ototoxic side effects
Aminoglycosides
▪ Their uptake by bacteria includes an Oxygen-linked energy dependent step
▪ Highly polar, poorly lipid soluble
▪ Poorly absorbed from the GI tract
What is the route of administration of Aminoglycosides?
IM or SC for systemic infections, dose-dependent effects Oral for enteric infections
How are Aminoglycosides distributed?
To the extracellular and transcellular fluids. Minimum into the CNS. accumulation in the renal cortex and otic endolymph
Resistance to Aminoglycosides is due to?
Due to inactivation of various bacterial enzymes (Amikacin and Plazomicin are unaffected)
What are the adverse effects of Aminoglycosides?
Relatively more toxic than other classes
▪ Nephrotoxic
▪ Ototoxic
▪ Neurotoxic (neuromuscular blockade) (rare)
Tetracycline
Chlortetracycline
Local and systemic bacterial, chlamydial, rickettsial,
and protozoal infections
Cows, sheep, horses, pigs
Oxytetracycline
Feed additive/growth promoters
Cattle, pigs
Doxycycline and Minocycline are used to treat?
- Respiratory infections and UTI
- Abscesses that do not respond to β-lactams
Dogs, cats = 1
Cats = 2
Tetracycline
Contracted tendons in foals
Horses
What is the route of administration of Tetracyclines?
Orally or every IV 8-12 hours
Doxycycline and minocycline are lipophilic and thus penetrate CNS, eye and prostate. (from PK section but she read this twice
Resistance of tetracyclines due to?
Due to decreased drug uptake or active transport of the tetracycline out of the bacteria cell.
Emphasized this
What are the adverse effects of tetracyclines?
▪ Nephrotoxic
▪ Discoloration of developing teeth
▪ GI suprainfections of fungi, yeast, or resistant bacteria
▪ Photosensitivity and hepatotoxicity (rare)
What is the function of Chloramphenicol (bacteriostatic)
Binds to the 50S ribosome and inhibit peptide bond formation and protein synthesis
What is the function of Macrolides?
Bacteriostatic
Bind to the 50S ribosome to prevent translocation of amino acids to the growing peptide chain and inhibit protein synthesis
What is the function of Lincosamides?
(bacteriostatic)
Bind to the 50S ribosome to prevent translocation of amino acids to the growing peptide chain and inhibit protein synthesis
What is the difference in structure between Chloramphenicole and Florfeincol?
See image from lecture
1 Hydrogen difference
What is the difference in function between Chloramphenicol and Florfenicol?
Bacteriostatic, bacteriocidal respectively
What is the difference in therapeutic uses between Chloramphenicol and Florfenicol?
Local and systemic infections
Resp infection, foot rot
What is the difference in animal use in Chloramphenicol and Florfenicol?
Dogs, cats, horses, birds
Cattle, pigs = resp infections, foot rot = cattle
What is the difference in PK in Chloramphenicol and Florfenicol?
- Absorbed from the GI, distributed
to all tissues including CNS and eye Hepatic metabolism - Absorbed rapidly from IM in cattle. Distributed to all tissues including CNS. Hepatic metabolism (1/3), urine excretion
What is the difference in the adverse effects of Chloramphenicol and Florfenicol?
Aplastic anemia
NO aplastic anemia
True or False: It is ILLEGAL to use chloramphenicol in food-producing animals
True
What are the therapeutic uses of Erythromycin?
What animals is this drug used on?
Gram +?
See slide
This is an alternative to penicillin
Enteritis pneumonia
Dogs, cats, horses; horses
What are the therapeutic uses of Azithromycin?
What animals is this drug used on?
St aphylococcus, Streptococcus, and Mycoplasma infections pneumonia
Dogs, cats, horses, foals
What are the therapeutic uses of Tylosin?
What animals is this used on?
Local and systemic infections caused by Mycoplasma and Gram (+) bacteria
Chronic colitis/IBD and respiratory issues
Dogs, cats
What is the route of administration of Macrolides?
Orally, Im
Where are Macrolides distributed to?
Distribution to all tissue except the CNS
Resistance to Macrolides occurs due to?
D ue to decreased binding to the 50S ribosome. Less frequently enzymatic inactivation
What are the adverse effects of Macrolides?
R elatively few side effects
▪ GI: abdominal pain, diarrhea
▪ Severe diarrhea in adult horses
What are the therapeutic uses of Lincomycin?
What animals is this used in?
Dysentery
Staphylococcal, streptococcal, and mycoplasma infections
Pigs
What are the therapeutic uses of Clindamycin ?
What species is this used in?
Periodontal disease, osteomyelitis, dermatitis, and deep soft tissue infections caused by Gram (+) bacteria
Dogs, cats
What are the therapeutic uses of Pirimycin?
What animals is it used in?
Bo vine mastitis
Cattle
What is the route of admin of Lincosamides?
Drinking water, IM, intramammary infusion
Resistance to Lincosamides occurs due to?
Due e to altered binding by bacterial ribosome. Cross-resistance between Lincosamides and Marcolides is common
What are the adverse effects of Lincosamides?
▪ Rare in dogs, cats, cattle and swine
▪ Severe, often fatal diarrhea due to altered GI flora in horses, rabbits, hamsters, and guinea pigs