Abx 3 (Inhibitors of Protein Synthesis) Flashcards
1
Q
Gentamincin
A
- Aminoglycosides
- Highly polar cations
- Does not cross cell membranes (not absorbed through GI)
2
Q
Streptomycin
A
- Aminoglycosides
- Highly polar cations
- Does not cross cell membranes (not absorbed through GI)
- Main use: 2nd line drug for active TB
3
Q
Amikacin
A
- Aminoglycosides
- Highly polar cations
- Does not cross cell membranes (not absorbed through GI)
- Least susceptible to inactivation (hospital use for resistant)
4
Q
Neomycin
A
- Aminoglycosides
- Highly polar cations
- Does not cross cell membranes (not absorbed through GI)
- OTC combo topical with polymyxin B & Bacitracin
5
Q
Doxycycline
A
-Tetracycline
6
Q
Tigecycline
A
-Glycycline
7
Q
Erythromycin
A
- Macrolide
- Inactivated by gastric acid
- Eliminated by hepatic CYP3A4 (interactions with other drugs)
- Admin orally in form of esters to improve bioavailability
8
Q
Azithromycin
A
- Macrolide
- Admin orally in form of esters to improve bioavailability
9
Q
Clindamycin
A
- Binds to 50S (blocks protein bond formation)
- Anaerobic and G+ aerobes
- Bacteriostatic (Bactericidal depending on dose/sensitivity)
- Should not be used in combo with macrolides or chloramphenicol
- Severe GAS, gas gangrene & Bacteroides fragilis
- Topical for acne
10
Q
Chloramphenicol
A
- Binds to 50S
- Bacteriostatic
- Anaerobes, G+(MRSA) & G-
- Widely distributed in tissue
- Metabolized by liver
- Used only for life-threatening situations (bacterial meningitis)
- Adverse reactions= Gray baby, bone marrow suppression (dose related) & aplastic anemia (not dose related)
11
Q
Linezolid
A
- Binds to 50S (unique site on 23S rRNA)
- Bacteriostatic
- MDR G+, VRE & MRSA
- Adverse reactions = reversible myelosuppression (so blood counts completed weekly)
- Neuropathy
- Interact with MAOIs & SSRIs (serotonin syndrome)
12
Q
Quinupristin-Dalfopristin
A
- Bactericidal
- Each drug separately is bacteriostatic
- G+
- Serious infections caused by VRE
- Adverse reactions = Hyperbilirubinemia & arthralgia; inhibits CYP3A4
13
Q
Aminoglycosides
A
Gentamicin
Amikacin
Streptomycin
Neomycin
14
Q
Aminoglycosides Mechanism of Action
A
- Bactericidal (cell death)
- G-
- Activity is concentration dependent
- Transport enhanced with cell wall inhibitors (passive diffusion through outer membrane & active through plasma membrane)
- Binds to 30S ribosomal subunit (misreading of mRNA & blockage of translocation)
15
Q
Aminoglycosides Therapeutic Uses
A
- Narrow spectrum
- Used in combo with beta lactams or vancomycin for resistant bacteremia/sepsis & G+ endocarditis
- Use sparingly/briefly to avoid toxicity