Pharm - exam 9 cell wall abx

What is bacteriostatic?

inhibits the growth of bacteria but does not kill them

What is bactericidal?

kills sensitive organisms

What are B-lactam abx?

work by blocking the formation of the peptidoglycan layer

What are glycopeptide abx?

work by disrupting the assembly of the precursor of the peptidoglycan precursor

What type of bacteria are beta-lactams more effected for?

gram positive; have a thicker peptidoglycan layer compared to gram negative

What are 2 examples of beta lactam antibiotics?

penicillin; cephalosporins

What is the #1 way bacteria form resistance to beta lactam abx?

altering their penicillin-binding proteins. These changes make it harder for the drug to attach to its target, so the abx cannot work as well. difficult to overcome.

#2 resistance mechanisms?

change to membrane permeability not allowing the abx in.

#4 resistance mechanims?

bacteria produce Beta lactamase enzyme that breaks the beta-lactam ring down which makes the abx not work.

When a drug is acid stable what does that mean?

stable in the stomach with acid so can be given PO

What are examples of acid stable penicillins?

amoxicillin, dicloxacillin, penicillin V

What does acid labile mean?

drugs that will not be stable in acid so must be given parenterally.

What are examples of acid labile penicillins?

penicillin G, piperacillin.

T/F: Penicillins are not safe to use in pregnancy.

false; they are safe

Most penicillins are eliminated by active renal rubular secretion except 2 drugs. What are the drugs and how are they elimilated?

oxacillin and nafcillin and they are cleared hepatically.

What is the drug of choice for syphilis?

Pen G

What pathogen is syphilis caused by?

Treponema pallidum ; so Pen G

How long does benzathine penicillin G provide sustained low-level coverage after IM injection?

3-4 weeks

What is the drug of choice for Listeria monocytogenes ?

ampicillin

Why abx might you prescribe to someone with an isolated pathogen of Strepococci, H. flu, E. coli?

amoxicillin

What often happens when a patient is given amoxicillin when they have an active mononucleosis infection?

rash

What can happen as an adverse effect when giving penicillin?

immediate IgE hypersensitivity causes hives and anaphylaxis.

What are the chances someone who took a penicillin without a reaction, will have a reaction in the future when taking a penicillin?

less than 1% of persons

What class is piperacillin in?

antipseudomonal

What pathogens is piperacillin effective for?

P. aeruginosa, Klebsiella

What is one example of a antistaphylococcal penicillin?

Nafcillin; when pathogen is sensitive to methicillin

What might you give to a patient who has a penicillin resistant strain of staphylococci?

dicloxacillin

What are clavulanic acid, sulbactam, tazobactam, and avibactam?

beta lactamase inhibitors

What are beta lactamase inhibitors?

potent inhibitors of beta-lactamases and can protect penicillins from inactivation by these enzymes.

A patient presents with CC of cat bite to anterior right forearm, what abx would you give?

amoxicillin/Clavulanate

How many generations of cephalosporins are there and what does each get better at?

5 generations; progressively greater spectrum, progressively greater gram negative effectiveness.

What is the difference in cephalosporins and penicillins?

they are more stable and less antigenic than penicillins

Most cephalosporins are excreted renally except 2. What 2 drugs are these and how are they excreted?

ceftriaxone and cefoperazone which are metabolized in the liver.

What are 2 examples of oral 1st generation cephalosporins?

cephalexin and cefadroxil

What is an example of a parental 1st generation cephalosporin?

cefazolin

What is cephalexin primarily used for?

skin and soft tissue infections and uncomplicated UTIs

What coverage do 1st generation cephalosporins have?

mainly gram-positive coverage (streptococci and methicillin sensitive staphylococci) and very limited gram-negative coverage except for E.coli UTI.

What is a drug of choice for surgical prophylaxis especially orthopedic procedures?

cefazolin - parenteral

What 2nd generation cephalosporin is available both orally and parenterally?

cefuroxime

What 3rd generation cephalosporin is active against P. aeruginosa?

ceftazidime

What is an example of a 3rd generation cephalosporin that shows hepatic excretion which allows for once daily dosing parenterally?

ceftriaxone

Cefepime has good activity against what pathogen?

P. aeruginosa

Cefepime is what generation cephalosporin?

4th generation

What is an example of a 5th generation cephalosporin?

cefiderocol

How does cefiderocol function?

functions as a siderophore which are iron chelating molecules secreated by bacteria that facilitate transport of iron into the bacteria

What class is ceftaroline in?

antistaphylococcal cephalosporin

Cefotetan may cause what type of reaction when taken with alcohol?

disulfiram-like

What cephalosporin can displace bilirubin from albumin?

ceftriaxone

What cephalosporin is contraindicated in neonates due to increased risk of kernicterus?

ceftriaxone