2/2/17 SMITH Antimicrobials II TEST #1 Flashcards
T/F Once the initiation complex is in place, the large ribosomal subunit assembles onto the small subunit and the initiation proteins disassociate.
True
What is the human cells closely resemble bacterial ribosomes?
-Mitochondrial ribosomes
What are the three big targets for protein synthesis inhibitors?
- 50S subunit
- 30S subunit
- tRNA synthetase
T/F Even at normal doses the protein synthesis antimicrobials are not selective between human mitochondrial ribosomes and bacterial ribosomes
False
They are normally selective for bacterial ribosomes
Where site does initiation occur in a ribosome?
-A site
Where does elongation occur in a ribosome?
-P site
T/F At high doses of protein synthesis antimicrobials toxicity occurs because selectivity is reduced
True
What are the 5 Aminoglycosides?
- Gentamycin
- amikacin
- Tobramycin
- Streptobycin
- Neomycin
What is the mechanism of action of the aminoglycosides?
-Bind to the 30s ribosomal subunit
What are three consequences of binding a drug to the 30s ribosomal subunit?
- blocked initiation of mRNA translation
- premature termination of mRNA translation
- misreading of the mRNA
What is the oldest aminoglycoside and has a high level of bacterial resistance?
-Streptomycin (IM and IV)
What is the most commonly prescribed aminoglycoside?
-Gentamycin (IV preferred)
What has the broadest spectrum of all aminoglycosides?
-Amikacin (IM and IV)
What aminoclycoside drugs has excellent activity against Pseudomonas aeruginosa?
-Tobramycin (IM and IV)
What aminoglycoside Drug is used primarily as topical for skin infections?
-Neomycin (topical only)
What protein synthesis antimicrobial drug is used primarily to treat infections caused by aerobic Gram - bacteria?
-Aminoglycosides
Are aminoglycosides bacteriostatic or bactericidal?
-Bactericidal (Once Daily dosing)
What type of drugs are aminoglycosides?
-Type I (concentration dependent)
Aminoglycosides are usually given IV or IM but the exception is what?
-Neomycin (topical)
What are four adverse effects of aminoclycosides?
- Ototoxicity
- Nephrotoxicity
- Neuromusclar paralysis
- Contact dermatitis
- Teratogenic
What groups of people are at most risk for the adverse effects of aminoglycosides?
- Elderly
- Impaired renal function
- Septic patients
- Previous exposure to aminoglycisides
What are four Tetracycline drugs?
- Tetracyclin
- Doxycycline
- Minocycline
- Tigecycline
What do tetracyclines target?
-Inhibit 30s subunit by blocking access of amino acyl-tRNA
What is the main clinical use for tetracyclines?
-Treatment of acne vulgaris
Tetracyclines are bacteriostatic or bactericidal?
-Bacteriostatic
T/F
If resistant to one TTC, then resistant to all TTC
True
-Except Tigeclycine
What type of protein synthesis antimicrobial concentrates in Ca2+ hydroxyapetite teeth/ bones?
Tetracycline
What type of protein synthesis antimicrobial has oral absorption altered by dairy, iron supplements or antacids?
-Tetracyclines
What type of protein synthesis antimicrobial has an adverse effect known as Disulfuram-like effect when taken while drinking alcohol?
-Tetracyclines
What are three superinfections that can occur as an adverse effect from tetracyclines?
- Candida
- Staphylococci
- Pseudomembranous colitis
What are two oral adverse effects of TTCs?
- Hairy tongue
- Deposition of bone and primary dentition (discolor teeth)
What drug was developed to overcome TTC-resistance in complicated skik soft tissue, and intra-abdominal infections?
-Tigecycline
What is the Safest antimicrobial drug?
-Macrolides (ketolides)
What are three macrolide drugs?
- Erythromycin
- Clarithromycin
- Azithromycin
