Micro 15 - Protein Synthesis Inhibitors Flashcards
What is the mechanism of action of Linezolid?
Binds to 23S RNA and interacts with the bacterial initiation complex.
In what clinical cases do we use Linezolid?
MRSA (Methicillin Resistant Staph Aureus) and VRE (Vancomycin Resistant Enterococci). Used orally (outpatient).
What is the mechanism of action of Tetracycline?
Binds to the 30s and prevents attachment of aminoacyl-tRNA. They are bacteriostatic and limited CNS penetration.
What are 4 commonly used tetracyclines?
Tetracycline, doxycycline, demeclocycline, minocycline.
How is Doxycycline eliminated?
Fecally, so it can be used in patients with renal failure.
What are the clinical uses for tetracyclines?
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Vibro cholerae, Acne, Chlamydia, Ureaplasma urealyticum, Mycoplasma pneumoniae, Tularemia, Helicobacter pylori, Borrelia burgdorferi, Rickettsia.
What substances must be avoided when taking tetracyclines?
Milk, antacids, Iron, calcium and magnesium.
What are the side effects of tetracyclines?
GI distress, Discoloration of teeth in children, Inhibits bone growth in children, photosensitivity.
What are the three medications that can cause photosensitivity?
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Sulfonamides, Amiodarone, Tetracycline.
What are 5 commonly used aminoglycosides?
Getamicin, Neomycin, Amikacin, Tobramycin, Streptomycin.
What is the mechanism of action of aminoglycosides?
Binds the 30s Ribosome. Bactericidal. Inhibits the formation of the initiation complex and causes misreading of mRNA.
What is the weakness of aminoglycosides?
It requires oxygen to work, therefore ineffective against anaerobes.
What are the clinical uses of Aminoglycosides?
Severe G(-) rod infections. They work synergistically with beta-lactam antibiotics (ampicillin with gentamicin in neonatal infections). Neomycin is used in Bowel surgery.
What are the side effects of aminoglycosides?
Nephrotoxicity (esp when used with cephalosporins). Ototoxicity (esp when used with loop diuretics). Teratogenic.
What are 3 commonly used macrolides?
Erythromycin, Azithromycin, Clarithromycin.