Call Wall/Membrane Targets Flashcards
what classes of drugs target cell wall/membranes
Penicillins
Beta lactamase inhibitiors
cephalosporins
monobactam (Aztreonam)
glycopeptides (vancomysin)
polypeptides (Bacitracin)
carbapenems
phophoenolpyruvate (fosfomycin)
what type agents are target the cell membrane
Lipopeptides (daptomycin)
Detergents (polymxinB)
___ antibiotics bind selectively to different PBPs and this contributes to sensitivity of bacterial strains to individual penicillins andchephalosporin antibacterials
B-lactam
Peptidoglycan is maintained by the enzymes that create the bonds between ____ peptidoglycan monomers and between ____ chains in the layer
NAM-NAG
what compounds do beta lactams include
penicillins
cephalosporins
monobactams
carbapenems
are beta lactam compounds bacteristatic or bactericidal
bactercidal
what are the natural and synthetic penicillin compounds?
natural: Penicillin G and V
synthetic: amoxicillin
What penicillins are beta-lactamase resistant
narrow or very narrow spctrum?
methicillin
nafcilin
oxacilin
*very narrow
Do natural or synthetic agents have a broader spectrum of activity
synthetic
MOA of penicillin compounds
bind and inhibit PBP enzymes
PBPs play important wall in synthesis and maintenance of bacterial cell wall peptidoglycans
Key adverse effects of penicillins
hypersensitivity
do penicllins treat gram negative or positive
+
Penicllin G or V: which one is given orally and which is given parenterally?
G = parenteral
V = oral
Pencillin G and V: narrow or very narrow or broad spectrum?
narrow
what are the broad spectrum penicillins
Ampicillin
Amoxicillin
Ticarcilin
Peperacilin
Ampicillin
Amoxicillin
Ticarcilin
Peperacilin
narrow or very narrow or broad spectrum?
broad spectrum
gram + and -
what broad spectrum penicillins should be combined with beta lactamase inhibitor
Ticarcillin
Piperacillin
which penicillin penetrates CSF of inflamed meninges of newborns
Ampicillin
B-lactamase inhibitor that can be used in combo with penicllin antibiotics
Clavulanic acid
e..g Amocillin and clavulanic acid = augmentin
what compound is used frequently if penicillins are not well tolerated
cephalosporin
Cephalosporins are more resistant to ____ compared to pencillins
beta-lactamase
MOA of cephalosporins
bind to and inhibit PBPs (penicillin binding protein)
key adverse effect of cephalosporins
hypersensitivity
cefazolin and cephalexin:
- generation?
- gram - or +?
- beta lactamase sensitivity?
- CSF penetration?
- first generation
- +
- sensitive
- No
Cefotetan, cefaclor, cefuroxime:
- generation?
- gram - or +?
- beta lactamase sensitivity?
- CSF penetration?
- 2nd generation
- and some -
- less sensitivity then 1st generation
- Cefuroxime (parenteral) only
Ceftriaxone, cefotaxime, cefdinir, cefixime (tri fixing dinner taxes)
- generation?
- gram - or +?
- beta lactamase sensitivity?
- CSF penetration?
- 3rd generation
- both
- increased resistance
- Ceftrixone and cefotaxime
Cefepime
- generation?
- gram - or +?
- beta lactamase sensitivity?
- CSF penetration?
- 4th generation
- both
- greatest resistance
- penetrates CSF
- Name a monobactam compound.
- gram + or gram -
- important features?
- beta-lactamase sensitivity?
- Aztreonam
- gram -
- penetrates CSF (for serious infections)*
- resistant
MOA of monobactam (Aztreonam)
inhibit PBPs
key adverse effect of monobactams (Aztreoname)
hypersensitivity (less than penicillin and cephalosporin)
which cell wall synthesis inhibitor/beta lactam antibiotics has the broadest spectrum of activity and are the most potent
Carbapenems (doripenem, imipenem**, ertapenem, meropenem)
what carbapenem is inactivated in the kidney?
what is it administered with to prevent inactivation?
Imipenem
cilastatin
Carbapenems key pharmacological effect is related to the ability of these agents to do what?
penetrate tissues and fluids very well - important for empriical tx of life threatening infections
Key adverse effects of carbapenems?
GI: nausea, vomiting, diarrhea
what cell wall synthesis inhibitor is used to treat MRSA and C. diff
Vancomycin (glycopeptide)
due to resistance development 1 use of vancomycin is limited to C. diff tx. Slow 2 is primary delivery route.
- oral
2. IV infusion
MOA of vancomycin
Binds to D-ala-D-ala pentapeptide and acts as a steric inhibitor – prevents elongation of peptidoglycan cell wall structure
Key adverse effects of vancomysin (glycopeptide antibiotic)
flushing (red neck or “red man syndrome”)
can vancomycin be used to treat meningitis?
Yes - penetrates CNS only when inflamed
what type of bacteria does vancomycin target
gram +
Bacitracin:
Targets gram 1 bacteria
Its use is restricted to __2_
- +
2. topical and opthalmic ointments
MOA of bacitracin
blocks incorporation of AA and nucleid acids into cell wall
Fosfomycin (phosphoenolpyruvate):
- commonly used in treating what?
- MOA
- uncomplicated UTI in females; safe in pregnancy
2. blocks early step in cell wall synthesis by preventing synthesis of UDP-N-acetylmuramic acid
Daptomycin (targets CM) is useful in treating what?
gram +, including MRSA (like vancomycin)
MOA of daptomycin
binds to membrane and causes depolarization of membrane - bactericidal
insertion into membrane is Ca2+ dependent
key adverse effects of daptomycin
musculoskeletal system: myopathy, rhabdomyolysis
___ is a detergent (CM target) that is often used topically to tx skin infections in combo with bacitracin
Polymyxin B
what bacteria does polymyxin B target
gram -
MOA of polymyxin B (detergent)
bidns to phospholipids in cell membrane and disrupts structure, specifically LPS
if someone has a penicillin allergy what drug may be used instead
Aztreonam (monobactam)
what drug is repelled by organism acquiring a + charge
daptomycin