Exam II: Antibiotics (Protein synthesis inhibitors + others)

Question 1

Erythromycin, clarithromycin, azithromycin.

Antibiotic class?

Answer 1

Macrolides

Question 2

Name the macrolide that does not end in “mycin”.

Answer 2

Fidaxomicin

Question 3

These two macrolides are modifications of erythromycin. What aspects of this drug have they improved?

Answer 3

Azithromycin and Clarithromycin

Improve oral absorption, half life, spectrum of activity and potency

Question 4

Structures contain 14-member macrocyclic lactone ring.

Name antibiotic class.

Answer 4

Macrolides “mycin”

Question 5

Three antibiotic drug classes that inhibits protein synthesis by binding to 50S ribosomal subunit.

Answer 5

Macrolides “mycin” except Fidaxomicin

Oxazolidinones “zolid”

Pleuromutilins “mulin”

Question 6

Most antibiotics that are protein synthesis inhibitors are bactericidal or bacteriostatic? Name exceptions.

Answer 6

Most are bacteriostatic

except aminoglycosides “mycin or micin”

Question 7

Antibiotic ending in “mycin” can be one of two types of antibiotics.

Answer 7

Aminoglycosides

Macrolides (3 drugs)

Question 8

This class of antibiotics is first choice for community-acquired pneumonia.

Answer 8

Macrolides “mycin”

Erythromycin, clarithromycin, azithromycin

Question 9

Can treat H.pylori, pertussis (whooping cough) certain STDs. Name the drug class.

Answer 9

Macrolides “mycin”

Erythromycin, clarithromycin, azithromycin

Question 10

This is the only macrolide used to treat gastroparesis.

Answer 10

Erythromycin

Question 11

This macrolide can cause dysgeusia (taste disturbances) as a side effect.

Answer 11

Clarithromycin

Question 12

Antibiotic classes that can cause QT interval prolongation.

Answer 12

Macrolides “mycin”

Lipoglycopeptides “vancin”

Question 13

What is Torsades de Pointes?

Answer 13

A possible side effect of certain antibiotics that prolong QT interval.

Ventricular arrhythmia

Question 14

Two macrolides most likely to have drug-drug interactions.

Answer 14

Erythromycin and clarithromycin

Question 15

Macrolides can interact with amiodarone. What is the possible effect? (Cardiac)

Answer 15

Both are QT prolonging agents

Question 16

This drug is one of the first to be found to cause an increased risk for C. diff infection.

Answer 16

Clindamycin

Question 17

These two drugs discussed so far can treat C. diff infections.

Answer 17

PO Vancomycin

PO Fidaxomicin

Question 18

This drug inhibits protein synthesis in bacteria and can also inhibit toxin production in necrotizing infections.

Answer 18

Clindamycin

Question 19

Why do some aminoglycosides end in “mycin” while others end in “micin”?

Answer 19

Derived from two different bacteria

Streptomyces - mycin

Micromonospora - micin

Question 20

Mechanism of action for aminoglycosides. Are they bacteriostatic or bactericidal?

Answer 20

Inhibit protein synthesis by binding to 30S ribosomal subunit

Bactericidal

Question 21

Aminoglycosides even have a post antibiotic effect. What does this mean?

Answer 21

Even when levels become undetectable, they still exert antibacterial activity

Question 22

What does the MIC line represent on a graph for bactericidal antibiotics?

Answer 22

Minimum inhibitory concentration - varies per drug

The lowest concentration (in μg/mL) of an antibiotic that inhibits the growth of a given strain of bacteria

Question 23

Time-dependent antibiotics vs concentration-dependent antibiotics.

Answer 23

Time-dependent antibiotics - greater effect when administered frequently. Longest duration over MIC.

Concentration-dependent antibiotic - greater effect with higher dose. Greatest peak over MIC.

Question 24

Can an antibiotic be both time and concentration dependent?

Answer 24

Yes, an antibiotic can be both time and concentration dependent.

Question 25

Antibiotics are considered broad spectrum for gram negative bacteria when they target what bacteria specifically?

Answer 25

Pseudomonas aeruginosa

Question 26

This drug class is broad spectrum and treats gram negative bacteria Pseudomonas aeruginosa.

Answer 26

Aminoglycosides "mycin"

Question 27

This drug class has a minimal effect on gram positive bacteria when used alone.

Answer 27

Aminoglycosides "mycin"

Question 28

Gram positive only. Name drug classes.

Answer 28

Glycopeptides "Vancomycin" Lipopeptide "Daptomycin" Lipoglycopeptides "vancin" Oxazolidinones "Zolid"

Question 29

Aminoglycosides are ______ - dependent bactericides.

Answer 29

Concentration-dependent

Question 30

Nephrotoxicity and Ototoxicity (ear damage) Name drug class. Reversible or irreversible?

Answer 30

Aminoglycosides Nephrotoxicity - reversible Ototoxicity - irreversible

Question 31

What are the two dosing strategies for aminoglycosides?

Answer 31

1. High dose over an extended period of time. | 2. Small doses given more frequently

Question 32

Two drug classes with narrow therapeutic index that require monitoring.

Answer 32

Aminoglycosides "mycin" Glycopeptides "vancomycin"

Question 33

This drug is the “workhorse” for serious gram- positive infections in hospital settings.

Answer 33

Glycopeptide Vancomycin

Question 34

Name the antibiotic dubbed "mississippi mud" originally due to impurities.

Answer 34

Glycopeptide Vancomycin

Question 35

Glycopeptide "Vancomycin" moa. Bacteriostatic or bactericidal?

Answer 35

Inhibits cell wall synthesis by binding to D-alanyl-D- alanine terminus of cell wall precursors Bactericidal

Question 36

Glycopeptide "Vancomycin" is a ______- dependent bactericide.

Answer 36

Time-dependent and concentration-dependent activity

Question 37

What two antibiotics can treat VRE infections?

Answer 37

Linezolid Daptomycin

Question 38

What does VRE stand for referencing antibiotics?

Answer 38

Vancomycin- resistant enterococci Some strains of Enterococci have become vancomycin resistant.

Question 39

IV vs PO Vancomycin. Name the difference in infections these are used to treat.

Answer 39

IV Vancomycin - Serious gram-positive infections PO Vancomycin - C. Diff infection

Question 40

What is "Red man syndrome" and how can it be avoided?

Answer 40

Histamine-mediated infusion reaction, not an allergic reaction. Limit infusion rate to avoid reaction.

Question 41

Fidaxomicin is a macrolide. Does it have the same moa as the others?

Answer 41

Fidaxomicin - Inhibits bacterial RNA polymerase Other Macrolides (Erythromycin, clarithromycin, azithromycin) - Inhibit protein synthesis by binding to 50S ribosomal subunit.

Question 42

Which drug out of the two discussed to treat C. diff has a reduced rate of infection? Why?

Answer 42

Fidaxomicin Drug possibly does a better job of preserving good bacteria in the gut

Question 43

Lipopeptide "Daptomycin" moa. Bactericidal or bacteriostatic?

Answer 43

Binds to cell membrane and causes rapid depolarization Bactericidal

Question 44

Any antibiotic with gram positive activity has an FDA approval for what clinical use?

Answer 44

Skin and soft tissue infections

Question 45

Why can't Daptomycin be used to treat pneumonia?

Answer 45

It is inactivated by pulmonary surfactant

Question 46

Daptomycin is only administered?

Answer 46

IV only

Question 47

Compare lipoglycopeptides "vancin" to vancomycin.

Answer 47

Longer half-lives than vancomycin Increased potency than vancomycin

Question 48

Lipoglycopeptides "vancin" moa. Bacteriostatic or bactericidal?

Answer 48

Inhibits cell wall synthesis by binding to D-alanyl-D- alanine terminus of cell wall precursors - Same as Vancomycin Bactericidal

Question 49

Additional moa that Telavancin and Oritavancin but Dalbavancin does not.

Answer 49

Disrupt cell membrane integrity

Question 50

The two lipoglycopeptides "vancin" administered as a single dose due to long half life.

Answer 50

Dalbavancin Oritavancin

Question 51

The only lipoglycopeptide "vancin" that can treat disorders other than skin and soft-tissue infections. Name the disorders.

Answer 51

Telavancin Hospital-acquired pneumonia, ventilator-associated pneumonia Bacteremia

Question 52

Lipoglycopeptide "vancin" are only administered?

Answer 52

IV only

Question 53

Oxazolidinones "zolid" moa. Bactericidal or bacteriostatic?

Answer 53

Inhibits protein synthesis by binding to 50S ribosomal subunit Bacteriostatic

Question 54

Oxazolidinone "zolid" most likely to interact with preserotonergic drugs.

Answer 54

Linezolid

Question 55

Pleuromutilins "Lefamulin" moa. Bacteriostatic or bactericidal?

Answer 55

Inhibits protein synthesis by binding to 50S ribosomal subunit Bactericidal or bacteriostatic