Exam 2- Antibiotics

Question 1

What are the beta lactams?

Answer 1

Penicillin
Cephalosporins
Carbapenems
Monobactams

Question 2

How do the beta lactams work?

Answer 2

They inhibit the peptidoglycan cell wall synthesis by binding to PBP protein which then inhibits transpeptidase from cross linking peptides between NAMs.

Question 3

How do G+ bacteria create resistance to beta lactams?

Answer 3

• reduce binding affinity of beta lactams to PBPs
• produce beta lactamases
• over production of PBPs (watering down)

Question 4

How can beta lactamase production be overcome?

Answer 4

Combining antibiotics with non-antibiotic

• Amoxicillin + clavulanate
• Ampicillin + sulbactam
• Piperacillin + tazobactam

Question 5

How to bacteria reduce affinity of beta lactams to PBPs?

Answer 5

incorporates antibiotic resistant bacterial DNA into the host cell which modifies the active site of the PBP and reduces the affintity

Question 6

What is the antibiotic resistance mechanism for Pseudomonas aeruginosa?

Answer 6

since antibiotics enter via porins, they make fewer porins

Question 7

What are the natural penicillins?

Answer 7

KONG V

Pen G and Pen V most common

Question 8

How is Pen G given and why?

Answer 8

IV or IM because it is susceptible to acid

Question 9

What are the side effects of natural penicillins?

Answer 9

hypersensitivity (anaphylaxis)

Question 10

What are natural penicillins given for?

Answer 10

narrow spectrum G+

Question 11

Why is methicillin no longer commonly used?

Answer 11

MRSA (bacteria created a new PBP)

Question 12

What antibiotics are beta lactamase resistant?

Answer 12

Methicillin

Nafcillin

Cloxacillin

Question 13

What is nafcillin commonly associated with? How is it cleared?

Answer 13

neutropenia (decrease in neutrophils)

cleared via biliary secretion

Question 14

How does Cloxacillin prevent beta lactamase from binding? How is it cleared?

Answer 14

large R chain

cleared by the kidneys

Question 15

What bacteria are beta lactamase resistant antibiotics used to treat?

Answer 15

narrow spectrum G+

** staphylococci and streptococci infections!! **

Question 16

What are the aminopenicillins?

Answer 16

Ampicillin

Amoxicillin

Pivampicillin

Question 17

How are aminopenicillins enhanced?

Answer 17

combining with clavulanate

Question 18

What are the side effects of aminopenicillins?

Answer 18

Rashes

Question 19

What conditions are aminopenicillins used to treat?

Answer 19

sinusitis, otitis media, chronic bronchitis, and epiglottitis

Question 20

What are the aminopenicillins susceptible to?

Answer 20

beta lactamases

Question 21

What antibiotic is used to treat pseudomonal infections?

Answer 21

piperacillin

Question 22

What is piperacillin indicated for?

Answer 22

bacteremia and pneumonia

pts with neutropenia

pseudomal infections

Question 23

What is the current concern about cephalosporins?

Answer 23

the extended-spectrum B lactamases produced by certain strains of E coli and Klebsiella

Question 24

What is the difference between penicillin and cephalosporins?

Answer 24

both have the same mechanism of action but cephalosporins tend to be more stable to beta lactamases giving them a broader spectrum

Question 25

What is the 1st generation cephalosporin antibiotics?

Answer 25

Cefazolin Cephalexin Cefalotin

Question 26

How is cefazolin given?

Answer 26

IV or IM

Question 27

If a patient with impaired renal function needed to be administered cefazolin, what would need to be done?

Answer 27

Dose would need to be reduced since cefazolin is cleared via kidneys ** if glomerular filtration/tubular secretion isn't working optimally, cefazolin cannot be cleared as effectively increasing concentration in the plasma **

Question 28

What antibiotic is given for surgical prophalactic?

Answer 28

cefazolin

Question 29

What are the 2nd generation cephalosporins?

Answer 29

Cefotetan Cefuroxime

Question 30

What is cefotetan often prescribed for?

Answer 30

G+ respiratory tract infections

Question 31

Which cephalosporin is has some anaerobic bacteria action?

Answer 31

cefuroxime

Question 32

What beta lactamase bacteria are the 2nd generation cephalosporins good for?

Answer 32

H. influenzae Moraxella catarrhalis

Question 33

What are the 3rd generation cephalosporins?

Answer 33

Cefotaxime Ceftriaxone

Question 34

What is cefotaxine good for?

Answer 34

G- and penicillin resistant bacteria

Question 35

What generation of cephalosporins cross the blood brain barrier?

Answer 35

3rd gen

Question 36

What are the 4th gen cephalosporins?

Answer 36

Cefepime

Question 37

What is the 5th gen cephalosporins?

Answer 37

Ceftaroline

Question 38

What antibiotic is used to treat MRSA?

Answer 38

Ceftaroline

Question 39

What drugs other than beta lactams target the cell wall?

Answer 39

vancomycin bacitracin fosfomycin

Question 40

What drugs target the plasma membrane?

Answer 40

daptomycin polymyxins

Question 41

Which antibiotic is known to cause C. diff colitis? What type of antibiotic is it?

Answer 41

clindamycin - it is a macrolide

Question 42

What are clindamycin used for?

Answer 42

anaerobic infections, MRSA infections, and cellulitis

Question 43

How do macrolides work?

Answer 43

they inhibit protein synthesis (50s)

Question 44

What are the side effects of the macrolides?

Answer 44

GI issues, deafness, increased QT interval

Question 45

What would treat H. pylori and what type of bacteria is it?

Answer 45

Clarithromycin- it is a G- microaerophilic spiral

Question 46

What are the macrolide antibiotics?

Answer 46

** mycin or in ending** clindamycin azithromycin clarithromycin