Fluroquinoloness FQ (Anti-Biotics)

Question 1

Name the 4 drugs of this class and their generations.

Answer 1

Ciprofloxacin (2nd gen), Norfloxacin (2nd gen), Levofloxacin (3rd gen), Moxifloxacin (4th gen).

Question 2

Are they bacteriocidal or static? Are the dose/time dependent or concentration dependent?

Answer 2

They are bacteriocidal and dose/time dependent.

Question 3

What’s special about Norfloxacin in terms of absorption as opposed to the other FQ’s?

Answer 3

Other FQ’s have good absorption, Norfloxacin does not.

Question 4

What can decrease the absorption of FQ’s?

Answer 4

It is impaired or decreased by food or drugs with divalent cations.

Question 5

How are FQ’s excreted? What is the exception?

Answer 5

They are renally excreted and thus require dose adjustments for the renally impaired. However, Moxifloxacin has partial hepatic metabolism and excretion.

Question 6

What’s special about the elimination of Moxifloxacin?

Answer 6

There doesn’t need to be dose adjustments for renally impaired but dose adjustments needed for hepatically impaired.

Question 7

What’s interesting about the 1st gen of FQ’s?

Answer 7

It only has one drug, Nalidixic acid, which would work for Gram neg bacteria only for the Tx of UTI’s. This isn’t used much.

Question 8

When would you use the 2nd gen FQ’s?

Answer 8

It’s good vs gram neg, esp cipro. Also good against MRSA, aerobic, enterobactericeae, pseudomonas, atypicals, and also TB. Not good vs strep or enterococci.

Question 9

When would you use 3rd gen FQ’s?

Answer 9

What you would use for 2nd gen, but in addition Strep (including pneumo, MSSA), E. Faecalis. Although it has activity against gram neg including pseudomonas, its less than Cipro. Also hits atypicals (like cipro) and mycobacterium spp (cipro only hits TB)

Question 10

When would you use 4th gen FQ’s?

Answer 10

It has good activity vs strep, including pneumo and MSSA like the 3rd gen, and for gram neg it has good activity against respiratory pathogens and enterobactericeae, POOR ACTIVITY vs pseudomonas. Also atypicals.

Question 11

Which FQ should we go to if we are treating gram neg?

Answer 11

Cipro, 2nd gen.

Question 12

What are the “Respirators FQ”?

Answer 12

This is the name given to the 3rd and 4th gen FQ’s, meaning very good vs strep pneumo, Haemophilis and Morsella, all of which causes respiratory infections.

Question 13

What is the MOA of FQ’s?

Answer 13

It inhibits DNA Gyrase and Topoisomerase IV during bacterial cell growth and reproduction, makes a FQ-enzyme-DNA tertiary complex that blocks the resealing step, promotes DNA breaking and cell death.

Question 14

What is the function of topoisomerase?

Answer 14

Releive torsonal strain during DNA replication.

Question 15

What is the function of DNA gyrase?

Answer 15

Relaxing the positive supercoiling of the DNA.

Question 16

What does blocking topoisomerase IV specifically induce?

Answer 16

Prevention of seperation of replicated chromosomal DNA into daughter cells.

Question 17

What organisms are FQ’s losing effictivity against due to increased resistance?

Answer 17

Pseudomonas (Cipro used to be great against it), Staph, C. Jejuni, Salmonella, Gonorrhea, S. pneumo and enterococci.

Question 18

If you have a resp infection, use…?

Answer 18

Levo, Moxi or Gemifloxacin, this treats strep pneumo and other resp pathogens.

Question 19

If you have a UTI, use…?

Answer 19

Cipro, norflox, or Levo/

Question 20

What causes Prostatis and what FQ’s treat it?

Answer 20

P. Aeruginosa, Enterobactericeae, and Enterocicc. Tx with Cipro or Levo.

Question 21

What causes Traveller’s diarrhea and what to use to Tx it?

Answer 21

Salmonella, Shigella, Campylobacter, enterotoxigenic E. Coli, and treat with Cipro or Levo, just like prostattis.

Question 22

What FQ’s to use for E. Coli 0157:H7 strand and what’s special about this strand?

Answer 22

This strand can cause HUS (Hemolytic-Uremic Syndrome by a shiga like toxin), and you CANNOT use FQ’s for this.

Question 23

What FQ’s to use for STDs?

Answer 23

None, FQ’s are generally ineffective against STD’s (like Gonorrhea to T. Pallidum) or we have other drugs that tx STDs better (C. trachomatus tx with doxy or azithro, etc).

Question 24

For Bone/Joint infections we can use…?

Answer 24

Cipro.

Question 25

What is one of the few times that FQ’s can be use as prophylaxis in kids?

Answer 25

Px for anthrax.

Question 26

Multidrug resistant TB we can use?

Answer 26

FQ’s seem to have activity against multidrug-resistant TB.

Question 27

GI AE”s of FQ?

Answer 27

Nausea, vomitting, diarrhea.

Question 28

HS rxns of FQ?

Answer 28

Almost as bad as sulfas, can also cause photosensitivity.

Question 29

CV problems with FQ’s?

Answer 29

QT prolongation like the macrolides

Question 30

CNS AE’s of FQ’s?

Answer 30

Minor stuff like headaches or dizziness, major stuff like seizures esp if taking other meds that make seizure more prone.

Question 31

What AE do we specially have to look out for in old patients, patients getting organ transplants or corticosteroids?

Answer 31

Tendon ruptures.

Question 32

What metabolic AE’s to look out for in FQ’s?

Answer 32

Glucose maintenance issues like hyper or hypo glycemia, potentially fatal.

Question 33

Myasthenia gravis and FQ’s? Secondary infections?

Answer 33

FQ’s can exacerbate MG and can cause resp failure as a result, can cause secondary infections of C. Diff and Candida.

Question 34

CYP interactions of FQ’s?

Answer 34

Cipro and Norflox are strong inhibitors of 1A2, Norflox in addition also inhibits 3A4.

Question 35

Theophyline + Cipro?

Answer 35

Seizures. Cipro on its own can cause seizures, and in addition theophyline is metabolized by 1A2, which Cipro inhibits; seizure is a major tox of theophyline.

Question 36

What CV DDI are we concerned with for FQ’s?

Answer 36

Anything that prolongs QT intervals like macrolides, TCAs, anti arrythmics and anti psychotics, among others.

Question 37

Patients taking glucocorticoids should not take FQ’s because of increased risk of?

Answer 37

Tendon ruptures. Also, older patients are more prone to this AE, as well as those receiving organ transplants (who are probably taking GC’s anyway).

Question 38

Divalent cations and ant-acids shouldnt be taken with FQ’s because?

Answer 38

It would decrease FQ absorption.