Antibiotics 2 Flashcards
Name all 4 B-Lactam compounds
- Penicillins
- Cephalosporins
- Monobactams
- Carbapenems
B-Lactam products are bacteriostatic or bactericidal?
Bactericidal
Penicillin G, Penicillin V, and Amoxicillin…which are natural and which are synthetic? What is special about methicillin?
Penicillin G and V are natural. Amoxicillin is synthetic.
Methicillin is B-lactamase resistant
How to B-lactams work?
Bind to and inhibit the Penicllin-Binding-Proteins (PBPs)…they play an important role in synthesis and maintenance of bacterial cell wall peptidoglycan
Key adverse effect of B-lactams?
Hypersensitivity…perhaps anaphylaxis.
What is expected if a patient has an allergic reaction to penicillin or B-lactam antibiotic?
If a patient has a severe reaction to penicillin, expect there to be a cross-reaction to other B-lactam antibiotics such as cephalosporins, monobactams, and carbapenems
Which 3 drugs are very-narrow spectrum and B-lactamase resistant
Methicillin
Nafcillin
Oxacillin
Which two drugs are narrow spectrum and B-lactamase sensitive?
Penicllin G
Penicillin V
Which two drugs are broad spectrum and B-lactamase sensitive?
Ampicillin
Amoxicillin
Which three drugs are extended spectrum and B-lactamase sensitive?
Piper had a tick in her ass
Piperacillin
Ticarcillin
Azlocillin
What drug is a B-lactamase inhibitor and is typically given with B-lactams?
Clavulanic acid
What is amoxicillin and calvulanic acid combination?
Augmentin
When are cephalosporins typically given?
What are cephalosporin resistance to B-lactamases compared to penicillins?
a. Agent used frequently if penicillins are not well tolerated.
b. In general, these agents are more resistant to β-lactamase as compared to penicillins.
MOA of cephalosporins?
Bind and inhibit the PBPs
Key adverse effect with cephalorsporins?
Hypersensitivity
1st generation cephalosporins (2)
B-Lactamase sensitivity
CNS penetration
Cefazolin
Cephalexin
B-lactamase sensitive
Do NOT enter CNS
2nd generation cephalosporins (3)
B-Lactamase sensitivity
CNS penetration
Cefotetan Cefaclor Cefuroxime B-lactamase sensitive Some enter CNS...not cefuroxime
3rd generation cephalosporins (4)
B-Lactamase sensitivity
CNS penetration
Ceftriaxone Cefotaxime Cefdinir Cefixime B-lactamase sensitive Most enter CNS
4th generation cephalosporins (1)
B-Lactamase sensitivity
CNS penetration
Cefepime
B-lactamase RESISTANT
ENTER CNS
Cephalosporins broaden out from gram positive
All handle gram positives.
1st generation only does gram positives
4th generation has the broadest spectrum of gram positive and gram negative bacteria
Monobactam compound
Aztreonam
Spectrum of activity for Aztreonam
CNS penetration
Treats
B-lactamase sensitivity
Limited to gram negative rods
Penetrates CNS well
Treats very serious infections (pneumonia, meningitis, and sepsis)
B-lactamase resistant
MOA of Aztreonam
Binds and inhibits PBP
Spectrum of activity of Aztreonam is limited to doing battle with
Gram negative rods only
Name 4 carbapenem compounds
Me and Dora Explored IMDB
- Doripenem
- Imipenem
- Ertapenem
- Meropenem
Spectrum of activity for carbapenems
Broad…covers gram negative and gram positive
Bacterial resistance to carbapenems
Due to bacteria expressing ‘carbamenemase’. Not sensitive to B-lacatamse
Which carbapenem is inactivated by the kidney? How to combat this?
Imipenem is inactivated by the kidney and is co-administered with CILASTATIN
Primary use of carbapenems
Penetrate tissues and CSF so used for EMPIRIC treatment of LIFE-THREATENING infections
MOA of carbapenems
Bind and inhibit PBP
Key adverse effect of carbapenems
GI disturbances: N/V/D
Name the only glycopeptide antibiotic
Vancomycin
Spectrum of activity of vancomycin
Used to combat which infections (3)
- Activity against GRAM POSITIVE bacteria and SOME gram negative bacteria
- Entercocci, MRSA, and C. Diff
MOA of vancomycin
Prevents elongation of the peptidoglycan cell wall structure by BINDING TO THE D-ALA-D-ALA PENTAPEPTIDE AND ACTING AS A STERIC INHIBITOR
*Masks the substrate like a boss
Key adverse effect of vancomycin
FLUSHING (RED MAN SYNDROME)
Name the only polypeptide cell wall inhibitor
Bacitracin
Spectrum of activity of Bacitracin
GRAM NEGATIVE and GRAM POSITIVE bacteria
Bacitracin use
Restricted to topical and ophthalmic ointments…it makes nice, moist, ointments
MOA of Bacitracin
Blocks INCORPORATION OF AMINO ACIDS AND NUCLEIC ACIDS into the cell wall
*Has nothing to do with PBPs
Name the only phosphoenolpyruvate cell wall inhibitors
Fosfomycin
Spectrum of activity of fosfomycin
Broad spectrum of activity against GRAM + AND GRAM _
MOA of fosfomycin
BLOCKS EARLY STEP in cell wall synthesis by preventing synthesis of UDP-N-acetylmuramic acid
*May or may not be important but fosfomycin is the only one that does anything even remotely close to that
