Antimicrobials 2 - Smith Flashcards
prokaryotes and Eukaryotes have what type of ribosomes?
prokaryotes = 70 S ribosome eukaryotes = 80 S ribosome
what is the composition of the 70S ribosome vs the 80S ribosome?
70S = 30S + 50S subunits = prokaryotes 80S = 40S + 60S subunits = eukaryotes
what drugs that target protein synthesis can target what 3 things?
- 50S subunit
- 30S subunit
- tRNA synthatase
what drugs target the 30S ribosomal subunit?
“Buy AT 30”
- Aminoglycosides
- Tetracyclines
What are the examples of Tetracycline drugs?
Tetracycline
Doxycycline
Tigecycline
Minocycline
what are the examples of Aminoglycosides?
Gentamycin Neomycin Amikacin Tobramycin Streptomycin
Aminoglycosides are bactericidal or bacteriostatic?
Aminoglycosides = bactericidal
Aminoglycosides function how?
Inhibits the 30S Subunit, of aerobic bacteria:
* Blocked initiation, Misreading at translation site, or premature termination
Aminoglycosides are clinically used in what?
severe gram negative aerobic bacteria
what are the risks of toxicity of Aminoglycosides?
- Nephrotoxicity- decrease dosage in renal function impaired patients
- Ototoxicity - # of destroyed hair cells
- Teratogen
- functional accumulation
what is the broadest spectrum aminoglycoside?
amikacin
what are the contraindications of tetracyclines?
- don’t give to: children under 8, pregnant women
- don’t take with milk, antacids, or iron tablets
how is tetracycline eliminated?
fecally eliminated
what is Tigecycline used to treat?
multi-drug resistant Strep pneumoniae, vancomycin resistant enterococci (VRE) and some anaerobes
what is the mechanism of tetracyclines?
Inhibits the 30S Subunit, preventing attachment of the aminoacyl-tRNA
tetracyclines are bactericidal or bacteriostatic?
bacteriostatic
what occurs if someone is allergic to 1 tetracycline, can they have another type of tetracycline?
- if allergic to 1 type they will be allergic to ALL types
Tetracyclines are good for treating what?
"VACUUM THe Bed Room" V- vibrio chlorae A- acne C- chlamydia U- ureaplasma U- not important M- mycoplasma pneumonia T- Tularemia H- H. Pylori B- Borreila burgdorferi (Lymes Disease) R - Rickettsia
location of prokaryotic vs eukaryotic translation?
- prokaryotes: continuous process of both transcription and translation in the cytosol
- eukaryotes: discontinuous process of transcription in the nucleus and translation in the cytoplasm
mRNA of prokaryotic vs eukaryotic translation?
- prokaryotes: polycistronic mRNA (1 mRNA can translate into multiple amino acids)
- eukaryotes: monocistronic
why can bacteria replicate sooo FAST?
b/c the process of translation is continuous (transcription and translation happen at the same time) and the prokaryotic mRNA is polycistronic
what drugs inhibit protein synthesis via tRNA synthetase?
only Mupirocin (Bactroban)
what is the mechanism of Mupirocin (Bactroban)
-reversibly inhibits isoleucyl tRNA synthetase
is Mupirocin bactericidal or bacteristatic? and against what?
bactericidal against gram positive and some gram negative bacteria
what is Mupirocin used to treat?
-topical treatment for MRSA, impetigo and Strep pyogenes
what drugs target the 50S ribosomal subunit?
"CCEL Quick at 50" C- chlorampenicol C- clindamycin E- erythromycin (macrolides) L- linezolid Q- quinpristin/ dalfopristin (streptogramins)
what are the Streptogramins?
Quinupristin/dalfopristin
what is the mechanism of Streptogramins?
inhibit 50S subunit
what are the clinical uses of Streptogramins?
- Life threatening bacteremia w/ VRE
- Enterococcus faecium;
- Complicated skin infections with S. aureus (VRSA)
what are the risks associated with Toxicity of Streptogramins?
Myalgia/ arthralgia
how is Streptogramins metabolized?
Streptogramins metabolized by the LIVER
Streptogramins are bactericidal or bacteriostatic?
bacteriostatic
Linezoid is bactericidal or bacteriostatic?
bacteriostatic
what is the mechanism of Linezoid?
Binds 50S subunit and blocks protein synthesis
clinically Linezoid is used for what?
- Healthcae associated pneumonia
- S. Aureus pneumonia
- Infections from MRSA and VRE
what are the risks associated with toxicity of Linezoid?
- serotonin syndrome (don’t give to patients on SSRI’s)
- bone marrow suppression
what drugs are considered Macrolines
- Erythromycin
- Azithromycin
- Clarithromycin
what is the mechanism of action of Macrolides?
Inhibits peptide translocation by binding to 50S
Macrolides are bactericidal or bacteriostatic?
bacteriostatic
what are the clinical uses of Macrolides and what bugs will they treat?
- Upper respiratory infections (sinusitis, otitis media, bronchitis), pneumonia, STD’s
- gram positive cocci chlamydia, Neisseria, mycoplasma, legionella
what are the safest antibiotics and why?
Macrolides are the safest antibiotics because there are low serum levels but the drug concentrates in neutrophils, macrophages and fibroblasts.
-can be taken orally
how is the mechanism of Azithromycin different from other macrolides and other antibiotics?
it does not inhibit cyt p450 enzymes
what is azithromycin effective against?
-respiratory infections due to H. influenza, Moraxella catarrhalis, mycobacterium (not TB)
Clindamycin is bactericidal or bacteriostatic?
clindamycin = bacteriostatic
what is the mechanism of action for clindamycin?
Blocks peptide bond formation of 50S Subunit
Clindamycin is clinically effective in treating what?
“Ann Cline was Always Positive she could C. things were Difficult”
- anaerobes
- Gram positive cocci (no gram negative activity)
what are the risks of toxicity with clindamycin?
overgrowth of Clostridium difficile (pseudomonas colitis)
what is the mechanism of action of chloramphenicol?
chloramphenicol - Inhibits 50S peptidyltransferase
chloramphenicol is bactericidal or bacteriostatic?
chloramphenicol = bacteriostatic
chloramphenicol is clinically effective in treating what?
- **it can cross BBB (meningitis)
- meningitis (patients w penicillin allergy)
- H. influenza
- Rickettsia
what is the risk of toxicity with chloramphenicol?
- gray baby syndrome
- anemia
- teratogenic
- inhibits cyt p450 enzyme
