L24: Other Cell Wall and Membrane Agents Flashcards
Aztreonam is the only drug that belong to which of the following groups….
A. Carbapenems
B. Monobactam
B. Monobactam
Ertapenem, Meropenem, and Imipenem + Cilastatin belong to which of the following groups?
A. Carbapenems
B. Monobactam
A. Carbapenems
_____, a monobactam that is useful for allergies, is active against Gram (-)
aerobic organisms but has NO activity against Gram (+) or Anaerobes
A. Ertapenem
B. Meropenem
C. Aztreonam
C. Aztreonam
Aztreonam is not cross allergenic with other β-lactams, except ____
ceftazidime
The inhaled nebulizer form of Aztreonam is used for..
A. P. aeruginosa in CF pts
B. UTI’s
C. Seasonal allergies
A. P. aeruginosa in CF pts
Neutropenia and GI symptoms are side effects of which type of Aztreonam administration?
A. Parenteral
B. Inhalation
A. Parenteral
True or False: Aztreonam can be used to treat serious infections, such as: UTIs, abdominal/gynecological infections, pneumonia, meningitis, or sepsis
True
Imipenem, Meropenem, Ertapenem belong to which group?
A. Carbapenems
B. Monobactam
A. Carbapenems
Which of the following Carbapenems is degraded by dehydropeptidases?
A. Imipenem
B. Meropenem
C. Ertapenem
A. Imipenem
____: Imipenem formulated with cilastatin to
inhibit dehydropeptidase
Primaxin
Which of the following Carbapenems has greater Gram (-) activity and less gram (+) activity compared to Imipenem?
A. Imipenem
B. Meropenem
C. Ertapenem
B. Meropenem
Which of the following Carbapenems does NOT enter CNS, is NOT used for P. aeruginosa, and is not typically used for empiric
therapy?
A. Imipenem
B. Meropenem
C. Ertapenem
C. Ertapenem
True or False:Carbapenems are oral agents with exceptionally broad spectra
False - carbapenems are PARENTERAL agents with exceptionally broad spectra
True or False: Carbapenems are active against E. faecalis (gram +) while inactive against
E. faecium and ORSA
True
True or False: Carbapenems are only active against Gram (+) and Gram (-) microbes
False - also Anaerobes!
Carbapenems are mostly reserved for nosocomial infections, but they can be combined with
____ for Pseudomonas treatment
aminoglycoside
____ alters membrane protein responsible for drug transport to keep carbapenems out.
However, there’s no cross resistance because they use different channel
than other beta lactams.
Pseudomonas
True or False:
Monobactams are agents of choice in organisms expressing ESBLs
False – Carbapenems!
Carbapenems have a dual MOA, which combines strong inhibition of ___ with inhibition of ___ enzymes
PBP (penicillin binding protein) and b-lactamase
Carbapenems are unaffected by, or even inhibit many β-lactamases, including some ___
ESBL’s
Carbapenems are vulnerable to carbapenamases
(e.g.Klebsiella pneumo carbapenemase, KPC) and some metallo-β-lactamase.
How can you overcome this?
Combine carbapenem with new beta lactamase inhibitors
(vaborbactam, relebactam)
Why can carbapenems cause seizures?
Can enter CNS
Risk of C. difficile
infection is higher with
broad spectrum
antibiotics such as
______
A.
B.
C.
C. carbapenems
Risk of C. difficile
infection is higher with
broad spectrum
antibiotics such as
______
A. Monobactam
B. Relebactam
C. Carbapenems
C. Carbapenems
Which carbapenem is most apt cause AE (e.g seizures)?
A. Ertapenem
B. Imipenem
C. Meropenem
B. Imipenem
True or False: Pseudomembranous
colitis is an AE associated with Monobactams
False - Pseudomembranous
colitis is an AE associated with Carbapenem !!!!
___ is a cell wall inhibitor of
gram-(+) organisms, as well as bactericidal, that prevents peptidoglycan
crosslinking by binding to
terminal D-alanyl-D-
alanine moieties
A. Dalbavancin (Dalvance®)
B. Bacitracin
C. Polymyxin B
D. Vancomycin
D. Vancomycin
For Vanco, resistance mechanisms
involve altered
peptidoglycan structure from alanine to ____
lactate
Vanco exhibits intermediate resistance, what does this mean??
Creates thicker walls to sequester drug
Why are Gram (-) bacteria not affected by Vanco??
Too large to penetrate OM
True or False: Vanco is a drug of last resort for strains highly resistant to beta-lactams. If it is sensitive fo beta-lactam, you should NOT use it
False -
Vanco is a drug of last resort for strains highly resistant to beta-lactams. If it is sensitive fo beta-lactam, you SHOULD use it
____ is standard treatment for ORSA (including: endocarditis). However, it can be given orally for C. dif in the gut or IV for catheters, spinal meningitis, or enterococcus infection
Vanco
For systemic therapy, vancomycin is
given by ____ ___ infusion
A. Slow, IM
B. Fast, IM
C. Slow, IV
D. Fast, IV
C. Slow, IV
Under which conditions will Vanco get into the blood stream? the CNS?
CNS
- High dose
- Inflamed meninges
BS
- High dose
- Inflamed GI
_____: drug-
induced release of histamine.This is not an allergic reaction, not involve IgE. Prevented by gradual Vanco infusion
over several hours
Red man syndrome
True or False: Ototoxicity and Nephrotoxicity (Mississippi mud) are AE associated with vanco
True
_____: is a lipoglycopeptide derivative of vancomycin, has BBW for nephrotoxicity, and treats skin infections caused ORSA (Gram +)
A. Dalbavancin
B. Telavancin
C. Bacitracin
B. Telavancin
____ is a glycopeptide notable for long
half life (8.5 days), which treats ORSA and Staph that is resistant to vancomycin
A. Dalbavancin
B. Telavancin
C. Bacitracin
D. Vancomycin
A. Dalbavancin
Bacitracin— a mixture of polypeptides produced
by Bacillus subtilis—inhibits _____ reactions necessary for cell wall synthesis
A. deamination
B. phosphorylation
C. dephosphorylation
C. alkylation
C. dephosphorylation
Which of the following works via: prevention of transport of cell wall
materials to site of synthesis?
A. Dalbavancin
B. Telavancin
C. Bacitracin
D. Vancomycin
C. Bacitracin
___ and ___ are resistant to Bacitracin
1) Enterobacteriaceae
2) Pseudomonas
Why is Bacitracin commonly given topically?
IV results in severe nephrotoxicity
Three primary uses of Bacitracin?
1) C. difficile colitis - oral
2) Conjunctivitis
3) Irrigate meninges
____ are cationic detergents that destabilize the Gram (-) cell membrane AND increase bacterial cell permeability
Polymyxins
____ is a mixture derived
from Bacillus polymyxa
____ is polymyxin E, from Bacillus colistinus
A. Polymyxin B; Colistin
B. Colistin; Polymyxin B
A. Polymyxin B; Colistin
True or False: Neosporin is a formulation
of neomycin, bacitracin,
and polymyxin B
True
____ can be: topical, ophthalmic, otic,
parenteral
______: parenteral only!
A. Polymyxin B; Colistin
B. Colistin; Polymyxin B
A. Polymyxin B; Colistin
Parenteral dosing of ____ are the last resort for
drug resistant gram (-) meningitis, respiratory,
septicemia, UTI
Polymyxins
What are the two primary AE associated with polymyxins?
1) Neurotoxicity
2) Nephrotoxicity
____ inhibits early step in
cell wall synthesis and is an analogue of phosphoenolpyruvate
A. Vancomycin
B. Fosfomycin
C. Polymyxin B or E
D. Daptomycin
B. Fosfomycin
Which of the following drugs inhibits enolpyruvate transferase to BLOCK
synthesis of UDP-N-acetylglucosamine,
a cell wall component + precursor of N-acetylmuramic acid??
A. Vancomycin
B. Fosfomycin
C. Polymyxin B or E
D. Daptomycin
B. Fosfomycin
Which of the following is active against gram (+/-) + is used for uncomplicated E. coli and Enterococcus faecalis UTIs??
A. Vancomycin
B. Fosfomycin
C. Polymyxin B or E
D. Daptomycin
B. Fosfomycin
Fosfomycin achieves high
concentration in and is in pregnancy cat B:
A. blood
B. urine
C. saliva
D. feces
B. urine
____ is a pore-forming membrane
destabilizer of gram-positive bacteria.
Involves calcium-dependent insertion into membrane, leads to DEPOLARIZATION, loss
of membrane integrity, and leaking of K+, ATP, etc.
A. Vancomycin
B. Fosfomycin
C. Polymyxin B or E
D. Daptomycin
D. Daptomycin
Uses of Daptomycin?
1) Resistant strains of MRSA, VRE
2) Complicated staph/strep skin infections
3) Bacteremia, endocarditis
True or False: Daptomycin is given IM and can be used use for community-acquired pneumonia
False - given IV and can NOT be used use for community-acquired pneumonia
Why does one have dark brown urine with Daptomycin use? Why does this occur?
High amounts of myoglobin
- Toxic to muscle
True or False: Most cell-wall targeted agents are β-lactams that use their
resemblance to peptidoglycan to inhibit bacterial enzymes
True
True or False: Bacteria can express β-lactamases and alter their PBPs to
escape
True
β-lactamase inhibitors can be paired with ____ abx
to increase their spectrum and efficiency
β-lactam antibiotics
