Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NRS 270: Pharmacology > Abx targeting cell envelope > Flashcards

Abx targeting cell envelope Flashcards

1
Q

Types of Beta-Lactams

A
  • Penicillins
    • Natural penicillins
    • anti-staph penicillins
    • aminopenicillins
    • beta-lactamase inhibitors + penicillins/ extended spectrium penicillins
    • extended spectrum penicillins
  • Cephalosporins
  • Carbapenems
  • Monobactam
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Natural Penicillins

A
  • Penicillin V = PO
  • Penicillin G = IV
    • Procaine Benzylpenicillin
      • duration is 15-20 hours
    • ​Benzathine Penicillin
      • low solubility
      • duration: 10-14 days
  • ​​G+ with a few G- (N. meningitidis, Hflu)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Anti-Staph Penicillins

A
  • cover G+, but not G- activity
  • bulky side chains prevent binding to beta-lactamases
  • Nafcillin
  • oxacillin
  • dicloxacillin
  • methicillin (no longer in use)
  • not effective against MRSA- good for other S. aureus infections
  • not used for strep or enterococci infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Aminopenicillins

A
  • amino group = increase hydrophilic nature = can pass through porins of gram negative bacteria more easily
  • Amoxicillin
  • ampicillin
  • tx: G+, and E.coli, Proteus, Salmonella, Shigella, H. Pylori, Listeria, N. meningitis
  • susceptible to beta-lactamase (penicillinase)
  • many gram negative bacteria have beta-lactamase = resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Beta-lactimase inhibitors

A
  • mimic penicillin and bind to the beta-lactamase which inhibits the beta-lactamase (penicillinase)
    • allows the drug to target the PBPs
  • Cluvalanate
  • Sulbactam and Tazobactam
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Extended Spectrum Penicillins

A
  • polar side chain allows greater penetration into gram negative bacteria
  • more resistant to gram negative beta-lactamases
    • still susceptible to beta-lactimase of staph
  • more active against gram - bacteria including pseudomonas
  • can be combined with beta-lactamase inhibitors
  • Drugs:
    • Piperacillin
      • broader spectrum than ticarcillin
    • Ticarcillin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

SEs of Penicillins

A
  • N/V/D
  • drug fever, rash
  • hepatotoxicity
  • neurologic toxicity
  • Urticaria
  • Angioedema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Extended spectrum penicilins + beta-lactamase inhibitors

A
  • broadest coverage, cover most enteric G- bacilli, and anaerobes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cephalosporins general info

A
  • 2 benefits of their structure:
    • more resistant to beta-lactamases
    • two side chains → creates more variations
  • Each generation covers broader aerobic G - (except 5th generation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

2nd generation cephalosporins

A
  • True Cephalosporins
    • PO: Cefaclor, Cefprozil, Cefuroxime axetil
    • IV: Cerufroxime sodium
    • active against G+ (same as 1st gen)
    • also covers G-: Hflu, Neisseria, and PEK
  • Cephamycins:
    • Cefotetan, Cefoxitin
    • methoxy group
      • resistant to beta-lactamases of anaerobes
      • loss of activity against staph and strep → methoxy group reduces affinity for PBPs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

3rd gen cephalosporins

A
  • PO: cefdinir, cefixime, ceftibuten
  • IV: cefotaxime, ceftazidime, ceftriaxone
  • covers HEN PEK–Hflu, Enterobacter, Neisseria
    • ​Proteus, E.coli, Klebsiella
  • **no activity against pseudomonas →adding a bulky side chain increases pseudomonas activity (ceftazidime) but makes you lose activity against G+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

4th generation Cephalosporins

A
  • Cefepime IV
  • Ceftolozane/tazobactam (IV)
  • modified R2 side chain improves activity against enterobacters (i.e. Klebsuekkam E.coli, salmonella, shigella)
  • **no loss of activity against G+ (unlike 3rd gen)
  • very limited anaerobic activity
  • covers: staph, strep, HEN PEK + Pseudomonas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

5th Generation Cephalosporins

A
  • Ceftaroline IV
  • cover staph, strep and MRSA
  • HEN + PEK but no pseudomonas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cefiderocol

A
  • MOA: 1st siderophore cephalosporin
  • Indication: Complicated UTI and pyelonephritis
    • caused by G- bacteria
  • Spectrum: G- aerobic/facultative
    • ​pseudomonas, Klebsiella pneumoniae carbapenemase (KPC)-producing enterobacteria
    • **no activity against G+ and anaerobes**
  • Dose based on creatinine clearance
  • SEs:
    • N/V/D/ C (leads to d/c of tx) and HA
    • infusion site rxn
    • rash
    • candidiasis, cdiff
    • cough
    • increase LFTs***/ HypoK ***
    • ***Hypersensitivity
    • thrombocytosis
    • stomatitis, seizure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Cephalosporin Toxicity

A
  • cross sensitivty with PCN allergy
  • relatively safe
  • rash, urticaria, anaphylaxis
  • reversible neutropenia, thrombocytosis, elevated LFTs
  • Cefotetan = hypothrmobinemia, disulfiram-like rxn
  • ceftriaxone = elimibated by biliary excretion = biliary sludge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Activity of 1st gen cephalosporin

A

staph, strep + PEK

17
Q

Activity of 2nd gen cephalosporin

A
  • staph, strep + HaN PEK
  • (Cefoxitin and cefotetan = mod anaerobic activity)
18
Q

Activity of 3rd gen cephalosporin

A
  • staph, strep + HEN PEK
19
Q

Activity of 4th gen cephalosporin

A
  • staph, strep + HEN + PEK +pseudomonas
20
Q

Activity of 5th gen cephalosporin

A
  • staph (including MRSA), strep, + HEN PEK
21
Q

Carbapenems

A
  • small molecules that use porins to gain accesss to periplasma of G- bacteria
    • structure is resistant to most beta-lactanases
    • broad range for PBPs from different bacteria
  • imipenem: staph, strep, listeria, HEN + pseudomonas
  • Doripenem: lower rate of resistance in pseudomonas
  • Ertapenem: lessa ctive against G+
    • no pseudomonas, and acinetobacter activity
    • once a day dosing
22
Q

Monobactams

A
  • Aztreonam: IV
  • only covers Gram -
  • completely synthetic
  • bind well to PBPs and resistant to beta-lactamases
  • excellent coverage of Hflu, Neisseria
  • intermediate coverage of pseudomonas
  • Toxicity:
    • rash,
    • toxic epiderma necrolysis
    • may induce eosinophilia
  • okay to use in pts with PCN allergy
23
Q

Glycopeptides Overview

A
  • structure is extremely large = cant pass through proins
  • → activity only against G+ (nearly all staph including MRSA) and strep
  • also good against anaerobic G+ (i.e. C.diff)
  • ex: vancomycin, telavancin, dalbavancin, oritavancin
24
Q

Vancomycin

A
  • glycopeptide (LARGE STRUCTURE)
  • Toxicities:
    • due to contaminants during purification process
    • Red man syndrome → infusion related syndrome
    • phlebitis
    • ototoxicity (associated with peak level)
    • nephrotoxocity (associated with trough level)
25
Q

Telavancin

A
  • glycopeptides
  • lipophilic side chain: enhances binding to peptidoglycan
    • pore formation and cell leakage
  • Toxicity:
    • Red Man Sxs
    • Diarrhea/N/V
    • Foamy urine
    • QT prolongation
    • Taste disturbances
    • interfere with coagulation test
26
Q

Daptomycin

A
  • cyclic lipopeptide abx, IV only
  • lipid portion inserts into the bacterial membrane creates channel →cell death
  • no activity against G-
  • activity against G+ including MRSA and some VRE
  • Poor activity in lungs = do not use to treat PNA
    • ​inactivated by lung surfactant
  • only use for skin and soft tissue infection (SSTI) and bacteremia/endocarditis
  • toxicity:
    • reversibly myopathy (only at higher doses)
    • phlebitis, rash, and GI effects
27
Q

Colistin

A
  • from the polymyxin group
  • cyclic decapeptide plus a fatty acid side chain
  • MOA:
    • positive charge bind to negative charge of lipopolysaccharide on outer membrane which dispaces calcium and magnesium →destabilizes the membrane
    • fatty acid tails inserts into membrane → increased permability →cell lysis
  • covers pseudomonas

NRS 270: Pharmacology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions