Anti-Infectives Part 2

Question 1

T/F: Carbapenams have cross reactivity with PCNs and cephalosporins.

Answer 1

True

Question 2

What was the first carbapenam, what is it coformulated with, and why?

Answer 2

Imipenem - coformulated with cilistatin bc imipenem alone is too nephrotoxic.

Question 3

T/F: Carbapenams are commonly used across many medical specialties.

Answer 3

False: carbapenams are very strong medications and use must be approved by an ID specialist.

Question 4

What is the only carbapenam that doesn’t cover pseudomonas?

Answer 4

Ertapenam

Question 5

List two important pharmacokinetic characteristics of carbapenams.

Answer 5

They are only available IV

They have excellent CNS penetration

Question 6

What is the biggest caution in using carbapenams and which carbapenam is of least concern regarding this caution?

Answer 6

They lower seizure threshold - meropenam has the least effect on seizure threshold.

Question 7

What are the three broadest spectrum beta lactams?

Answer 7

Cefepime (4th gen cephalosporin)
Zosyn (Piperacillin + Tazobactam)
All carbapenams except ertapenem

Question 8

What do the three broadest spectrum beta lactams cover?

Answer 8

Gram positive (including MSSA and Strep), and gram negatives including pseudomonas.

Question 9

What do the three broadest spectrum beta lactams NOT cover?

Answer 9

MRSA, Vancomycin Resistant Enterococcus (VRE), and atypical bacteria

Question 10

What does vancomycin cover and not cover?

Answer 10

Very powerful against gram pos - MRSA and enterococcus. Does NOT cover gram neg.

Question 11

What is a caution in the use of vancomycin?

Answer 11

Nephrotoxicity

Question 12

What specialties can order use of vancomycin?

Answer 12

ID team must approve long term use.

Question 13

How is vancomycin administered and what are its uses?

Answer 13

PO: not absorbed - used only for C Diff

IV for any other use

Question 14

What is Red Man’s Syndrome and how is it resolved?

Answer 14

Excess HST release when vancomycin is administered too quickly - slow the infusion rate.

Question 15

What do the macrolides cover?

Answer 15

Hodge-podge of gram pos and gram neg plus the atypicals.

Question 16

List three atypical bacteria covered by macrolides.

Answer 16

legionella, mycoplasma, some chlamydia strains

Question 17

What disease does legionella cause?

Answer 17

Community acquired pneumonia with GI symptoms

Question 18

List three macrolides and what is unique about each.

Answer 18

Erythromycin: must be dosed qid
Clarithromycin: doesn’t require qid dosing
Azithromycin: used w/ ceftriaxone to treat chlamydia and gonorrhea and doesn’t require qid dosing

Question 19

When are macrolides typically used in management of gram positive infections?

Answer 19

In patients allergic to PCN.

Question 20

What is true about allergic reactions to macrolides?

Answer 20

Allergy is rare and often misreported

Question 21

What is a unique side effect of clarithromycin?

Answer 21

Metallic taste develops about an hour after admin.

Question 22

What drug is known as a Z-Pack and how is it dosed?

Answer 22

Azythromycin - 500mg on day 1 and 250mg x 4 days

Question 23

What is the IV dosing of azythromycin?

Answer 23

500mg x 5 days (long half life)

Question 24

What STI is treated with azythromycin? What is the dose for this use? What other STI is treated simultaneously and what should also be tested for?

Answer 24

Chlamydia - 1g
Treat gonorrhea concurrently with ceftriaxone
Also do an RPR to test for syphilis

Question 25

What do the tetracyclines cover?

Answer 25

Hodge-podge of gram pos and neg plus tickborne diseases (RMSF and Lyme)

Question 26

Tetracyclines are chelating agents. What does this mean and how is the effect managed?

Answer 26

Binds to heavy metals and then will not absorb. Space administration from ingestion of milk, yogurt, multivitamins, etc.

Question 27

What is the first line abx for early Lyme disease?

Answer 27

Doxycycline

Question 28

What is minocycline used for?

Answer 28

``` acne - kills the causative bacteria and has anti-inflammatory properties. Neisseria Meningitidis (meningococcal meningitis) ```

Question 29

In what patients should tetracyclines not be used and why?

Answer 29

Pregnant females and kids under 8. It will bind Ca and cause teeth yellowing and deformities.

Question 30

What do fluoroquinolones end in and what are some examples?

Answer 30

All end in oxacin - ciprofloxacin, norfloxacin, ofloxacin

Question 31

What is the mechanism of action fluoroquinolones?

Answer 31

Bind and inhibit DNA-gyrase. DNA-gyrase is an enzyme that unwinds DNA for replication.

Question 32

What is the father of the fluoroquinolones, how is it administered, and what are its uses?

Answer 32

Ciprofloxacin (PO) - pseudomonas, chlamydia, and anthrax.

Question 33

What are newer fluoroquinolones most commonly used for and what do they not cover?

Answer 33

gram pos - especially in community acquired pneumonia. No coverage of pseudomonas.

Question 34

List two examples of fluoroquinolones.

Answer 34

Ofloxacin and Levofloxacin

Question 35

What do fluoroquinolones have in common with the macrolides?

Answer 35

Cover atypicals - macrolides do it better

Question 36

What is a concerning adverse effect of fluorquinolones and what is its black box warning?

Answer 36

AE: QT prolongation | Black Box: tendon ruptures

Question 37

What two abx classes cover atypical bacteria?

Answer 37

macrolides and fluoroquinolones

Question 38

What do fluoroquinolones have in common with tetracyclines?

Answer 38

They are chelators - avoid milk, yogurt, multivitamins.

Question 39

In what patients should fluoroquinolones be avoided and why?

Answer 39

Pregnant females and children under 18 because of soft tissue malformation.

Question 40

How are fluoroquinolones eliminated?

Answer 40

Renally