Macrolides Flashcards
What is the MOA for the tetracyclines?
30S inhibitors
Is the MOA of the tetracyclines reversible or irreversible? Bacteriostatic or bactericidal?
Reversible –> Bacteriostatic
Which 4 organisms are sensitive to the Tetracyclines?
- Brucella
- Rickettsia
- Spirochetes
- Chlamydia
Which is energy-dependent, the uptake of Tetracyclines in gram (+) bacteria or gram (-) bacteria?
Gram (-)
In which environments is gram (-) uptake of Tetracyclines poor?
- Anaerobic conditions
2. Low pH
____ is a neuroprotective agent that inhibits apoptosis in neurons.
Minocycline
____ is a good choice in the presence of a neuropathy because it is NOT eliminated via the kidneys.
Doxycycline
Tetracyclines are chelated by what?
- Mg+2
2. Ca+2
Because Tetracyclines are chelated by Mg+2 and Ca+2, they are poorly absorbed in the presence of what?
Milk
Tetracyclines also cause what in the fetus, neonate, and juvenile?
Tetracyclines are deposited into bone and teeth and cause YELLOW DISCOLORATION
Which Tetracycline does NOT cause the yellow bone/teeth discoloration?
Minocycline
List the 5 other toxicities associated with the Tetracyclines.
- Nephrotoxicity
- GI effects
- Esophageal stricture
- Injection site irritant
- Photosensitivity
Which Tetracyclines are NOT associated with nephrotoxicity?
- Doxycycline
2. Minocycline
Which Tetracycline causes esophageal stricture in the cat?
Doxycycline
What are Tetracyclines use vs. in foals?
Contracted tendons
Which Tetracycline is commonly use vs. BRD (bovine respiratory disease)?
Hexasol
Oxytetracycline + Flunixin
What is the MOA of the macrolides?
Bind to the 50S ribosome to interrupt tRNA binding and peptide chain elongation.
Is the MOA of macrolides reversible or irreversible? Bacteriostatic or bactericidal?
Reversible –> Bacteriostatic
What is the spectrum of the Macrolides?
- ALL gram +
2. Gram (-) anaerobes
Most Macrolides are NOT effective against which bacterial group?
Enterobacteriaceae
Which Tetracycline is the BEST versus Mycoplasma?
Tulathromycin
Which of the following is effective and which is ineffective against Mycoplasma: Erythromycin, Tylosin?
Erythromycin is NOT effective
Tylosin is usually effective
How do Macrolides primarily gain resistance?
Methylation of the ribosome
The methylation associated with Macrolide resistance confers cross-resistance with which two antimicrobial classes?
- Lincosamides
2. Streptogramins
Which 2 Macrolides cause sterile abscesses?
- Tylosin
2. Erythromycin
Which Tetracycline is cardiotoxic in the human?
Tilmicosin
Which Macrolide prevents tear staining due to epiphora?
Tylosin
In which species should Tylosin NOT be used?
Equine
What are the top 3 uses of Tulathromycin?
Bovine and swine (1) respiratory disease, (2) foot rot, (3) pink eye.
What is the main indication for the use of Clarithromycin?
Vs. Rhodococcus in the horse (+ rifampin)
What is Tylosin used vs. in poultry?
Mycoplasma
What is Tylosin used vs. in dogs?
- Epiphora
2. IBD
What is Tylosin used vs. in swine?
- Mycoplasma
2. Brachyspira
What is the spectrum of the Macrolides?
- Gram (+)
2. Gram (-) anaerobes
