Lecture 44 - Protein Synthesis inhibiting Anti-microbials Flashcards
Aminogylcosides
- Common Agents
- Mechansim
- Bactericidal vs Bacteriostatic
Gentimicin
Amikacin
Binds 30S subunit; misreads or terminates genetic code, inhibiting bacterial protein synthesis
Static at low doses; Cidal at high doses
Aminoglycoside:
- Adverse Events
- Spectrum of Activity
- Clinical uses
- Ototoxicity- Cochlear and vestibular damage; Dose related and Irreversible. Nephrotoxicity
- GNs (including Pseudomonas, but not first choice); Used in synergy with B Lactams for GPs. No Anearobic coverage
- Great for UTIs; Serious GN infections; used in hopital only
TetraCyclin - common agent - Mechanism - Static or Cidal ? Resistances
- Doxycyclin
- Reversibly Bind to 30S; block acess of tRNA to mRNA; inhibit protein synthesis; lipophilic
- Bacteriostatic.
Ribosomal Protection Proteins; Active Efflux
TetraCyclin
- Adverse Events:
Spectrum
Clinical Uses
hypoplasia of the teeth; stunted growth; photosensitivty
Broad GN, not pseudomonas; GP - staphylocci (some CA MRSA) and streptococci; some anaerobic activity; Some atypicals (chlamydia, mycoplasm)
Bronchitis and CA PNA; STIs
Glycylcyclines
Common Agents
Mechanism
Spectrum
Tigecyclin - synthetic derivative of tetracyclin
Overcomes resistance of Tetra Cycline
Very Broad: GN (Except Pseudo, proteus); GP – Staph inclduing MRSA), Strep, Enterococci (including VRE); Most anaerobes
Macrolides
- Common Agents
- Mechanisms
- Resistances
- Static or Cidal
Azithromycin
Erythromycin
Clarithromycin
Mechanism: Binds 50S subunit; blocks translocation
Resistances; Erm gene alters target
Static
Macrolides
- Adverse effects
- Spectrum
- Clinical uses
-Adverse Effects: N, V, Prolonged QT
- Spectrum: GN, GP, atypicals
(not pseudomonas)
Clinical: CA PNA, atypical PNA, STIs, Diarrhea
The most common abx given at the clinic
Lincosamides:
- Common Agent
- mechanism
- Resistance
- Cidal vs Static
Clindamycin
binds to 50S; blocks translocation;
Inducible Clindamycin Resistance (mediated by Erm gene).
bactericidal at high doses
Lincosamides:
- Adverse events
- spectrum
- Clinical
C diff infection. Classically associated with clindamycin
No activity against GN; Good GP activity: (Staph - some CA MRSA, and Strep); Anaerobes (“above the diaphragm”; including bacteroides fragilis)
CA aspiration PNA; Oral ENT infections; human bite wounds; absecessed; skin and soft tissue infection due to CA MRSA
Oxazolidinones
- Common Agents
- Mechanism
- Static vs Cidal
- Adverse events
Linezolid
Tedizolid
Binds 50S; prevnts formation of 70S complex; inhibit translocation.
Bacteriostatic;
Linezolid: Bone Marrow Supression (thrombocytopenia); Inhibits Monoamine Oxidase Acitivity (Serotonin syndrome when given with SSRIs). Lactic acidosis
Tedizolid: Do not see serotonin Syndrome
Oxazolidinones
- Spectrum
Clinical uses
GP Only - Staph (including MRSA); Strep; Enterococci (including VRE)
VRE, PNA due to MRSA; Complicated skin and soft tissue infections
Mupirocin Mechanism Adverse Events: Spectrum Clinical uses
binds reversible to tRNA synthetase;
topical use only
Adverse Events: None
(but made with polyethylene glycol which may have cause contact dermititis
GP - Staph and Strep. No activity against Enterococci. Doesn’t kill off Commensal, healthy bacteria
Skin infections – impetigo, folliculitis - of SA and Strep pyogenes. MRSA deconlonization of nares; Prophylaxis against catheter infection (abx coated catheters)
DNA Synthesis Inhibitors:
Class:
Common Agents
Mechanism
Class: Imidazoles
Common Agents: Metronidazole (US)
Tinidazole (europe)
Mechanism: Enter bacteria by diffusion; produce free radicals; leading to cytotoxic effects
Imidazoles:
Adverse effects
Spectrum
Clinical uses
Metallic Taste; CAN (HA, vertigo); Disulfram like effect with Etoh (vomiting, flushing)
Anaerobes “below the diaphragm”, including bacteriodes fragilis; Protozoa
Anerobic Infections - C DIFF!!; intra-abdominal infections/abscesses
