• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

image

PLAY BUTTON

image

PLAY BUTTON

image

Progress

1/50

Click to flip

Card Range To Study

through

50 Cards in this Set

  • Front
  • Back
Hydrolysis of the B-lactam ring yields?
Penicilloic acid:
lacks antibacterial activity
substituents attached to what biological group, yield modified penicillins?
amino group
basic structure of penicillin
Thiazolidine ring attached to a B-lactam ring that carries a secondary amino group.
Penicillins have activity against what organisms?
Gram +
Gram - cocci
Non B-lactamase anaerobes
Penicillin has little activity against
Gram - rods
B-lactamase producers
Resistant to staphylococcal B lactamase
Nafcillin
Similiar to ampicillin but better absorbed
Amoxicillin
Ampicillin
Similar to penicillin but with greater activity against gram - and its also acid-stable
MOA of penicillin
Inhibit bacterial growth by interfering with transpeptidation of the bacterial cell wall synthesis. B-lactams bind to the PCP of the D-ALA-D-ALA peptide that is attached to NAM and stops it from binding to another D-ALA-D-ALA peptide of another NAM.
B-lactam antibiotics only work when the bacteria is actively
growing and synthesizing cell wall
Mos common resistance to B-lactams
beta-lactamases
Basis of resistance to B-lactams in MRSA and penicillin resistance in pneumococci and enterococci
Altered target PBP's
Resistance due to impaired penetration of antibitotic to target PBP's occurs only in gram- species because?
they have an impenetrable outer wall that is absent in gram+
How do B-lactams work against gram- bacteria?
They cross the outer cell wall via porin channels
B-lactam that is highly bound to proteins
Nafcillin
Penicillin is rapidly cleared via? Nafcillin?
Ampicillin?
tubular excretion in the kidneys. Thus, the dose must be adjusted in those with renal failure.
Biliary excretion
Kidney
Should penicillins be given with food?
Except for amoxicillin, no, because they may bind to food proteins, and may also be inactivated in a highly acidic environment.
Effective in the txmt of syphilis
Benzathine penicillin G:
IM penicillinG
Adverse effect of methicillin. Nafcillin?
interstitial nephritis
Neutropenia
Implicated in pseudomembranous colitis
Ampicillin:
may also cause Nausea and diarrhea
B-lactams that are resistant to beta-lactamase producing staphylococci
Methicillin and nafcillin
Active against staphylococci and streptococci, but not against enterococci, anaerobes, or gram- rods/cocci
Antistaph penicillins:
Methicillin and nafcillin
Broad-spectrum penicillins. Are they resistant to b-lactamases?
Ampicillin
Amoxicillin
Piperacillin
Ticarcillin
They are not resistant, even though they are effective against L. monocytogenes, E. coli, H. influenzae and others.
DOC for infections of streptococci, staphylococci, enterococci, meningococci
Penicillin
Ampicillin is synergistic with aminoglycosides in what type of infections?
Listeria or enterococcal
given orally to treat UTI's, sinusitis, otitis, and lower respiratory tract infections
Amoxicillin or ampicillin
B-Lactams that have activity against gram- rods including pseudomonas, enterobacter, and Klebsiella. What if you have anaphylatic allergic rxn to penicillins?
Piperacillin and ticarcillin
Wide spectrum b-lactamase susceptible drugs

Carbanapems:
Imanapem
Nucleus of cephalosporins
7-aminocephalosporanic acid
1st generation cephalosporins
cephazolin, Cephalexin
Cephalosporin used as prophylaxis txmt before surgery
cefazolin
MOA of cephalosporins
Bind to PBP's and inhibit bacterial wall synthesis
Excretion of cephalosporins
Via tubular cells of kidney
Alternative to antistaphylococcal penicillin for pts allergic to penicillin
Cefazolin:
Good activity against gram+ organisms and is resistant to some beta-lactamases
B-lactam DOC for penicillin-resistant pneumococci
ampicillin or amoxicillin
Ampicillin, ticarcillin, and piperacillin are usually combined with what to increase their activity
B-lactamase inhibitors:
clavulanic acid, sulbactam, or tazobactam.
DOC for gonnorhea
3rd generation cephalosporins:
Ceftriaxone
Cefixime
Most active cephalosporins against penicillin resistant pneumocci
Ceftriaxone and cefotaxime...used in meningitis. 3rd gen cephs.
3rd generation cephalosporins should be avoided in txmt of?
enterobacter infections due to emergence of resistance. Instead use 4th gen cefipime.
Used in txmt of sepsis of unkown cause in pts who are immunocompromised
3rd generation cephalosporins:
Cefdinir(Omnicef)
Ceftriaxone(rocephin)
Cefotaxamine
Useful characteristics of of 3rd generation cephalosporins
Expanded gram- coverage and cross the blood brain barrier
Cephalosporin useful in the txmt of enterobacter
4th gen:
Cefipime
Should pts with a hx of anaphylaxis after penicillin administration be given cephalosporins
No
Carbapenems
Imipenem, Meropinem, and ertapenam
Only monobactam available in the US. What is it used for?
Aztreonam:
Aerobic gram+ bacteria such as Pseudomomas
Beta-Lactamase Inhibitors are most active against bacteria with?
Class A beta lactamases:
Plasma encoded
Not useful for inducible chromosomal beta-lactamases
Inhibits transglycolase, thus preventing elongation of petidoglycan chains
vancomycin
Antimetabolite that blocks the incorporation of D-Ala into the pentapeptide side chain of the peptidoglycan. When is it used?
Cycloserine:
Used during resistant tuberculosis strains, when the 1st line txmt did not work. Causes neurotoxicity.
Bacitracin is active against? MOA
Gram+
Stops dephosphorylation of lipid carrier that transfers peptidoglycan units to cell wall.
Highly nephrotixic, so its used only topically.
Used in vanc resistant strains of enterococci and staphylococci
Daptomycin:
causes K+ efflux
SE of daptomycin use
May cause myopathy, so levels of CPK should be checked