Treatment of Respiratory Tract Infections

Question 1

tx of maligant EO

Answer 1

must use Ab that cover pseudomonas - main cause of MEO

• 1st line: CIPROfloxacin, LEVOfloxacin
• if flouroquinilones C/I
  
  • pt then hospitalized to be given:
    
    • IV B-lactam
      
      • piperacillin-tazobactam, cefe_pime,_ certazidime
    • if ESBL (B-lactam resistant)
      
      • meropenem, imipenem-cilastin

Question 2

what to give for malignant OE if pt cant take flouroquinilones because of AEs/ are C/I?

Answer 2

example: tenosynovitis, glucose dysregulation, long QT interval

next choice is: B-lactams with pseudomonas coverage:

• piperacillin-tazobactam
• “pime and dime”

if psuedomonas resistant to B-lactams: meropeneum, imapenem

Question 3

otitis media tx

Answer 3

ab must cover s. pneumonia, h. influenza, m. catarrhalis

• amoxicillin - 1st line
• if allergic to penicillins: cef_dinir,_ cefpodoxime (oral 3rd gen cefs)
• if allergic to all B-lactams: doxycycline

Question 4

what is the most common reason for treatment failure of otitis media?

what do we prescribe next?

Answer 4

h. influenza & m. catarrhalis produce penicillinases & cephalosporinases, knmocking out 1. amoxicillin and 2. cefdinir, cefpodoxin

give:

• amoxillin-_clavulante_
• doxycyline
  
  • 3rd choice for OM anyways

Question 5

tx acute sinusitis

Answer 5

must cover s. pneumonia, h. influenza, m. catarrhalis -same as OM*. thus, Ab are same as OM.

• amoxcillin / amoxicillin-clauvulante*
• cefdinir, cefpodoxine
• doxycyline

Question 6

chronic sinusitis tx

Answer 6

must cover s. aureus & anaerobes. this happens to be same Abs that cover OM & acute sinusitis.

• amoxicillin-clavunate
• cefdinir, cefpodoxime + clinda / metro
• doxycyline
• resp flouroquinilone + clinda / metro

Question 7

treatment of OM vs acute sinusitis vs chronic sinusitis

Answer 7

all the same: amoxcillin top choice, then cefdinir/cefpodoxinme if allergic to B-lactams, then doxy if allergic to cephs.

difference is that amoxicillin-clavaunte is more of a top choice in sinusitis, whereas is it givin in OM only after treatment failure.

Question 8

tx for COPD exacerbation?

Answer 8

m/c agents of COPD exacerbation are OM agents - s. pneumonia, h. influenza, m. catarrhalis + legionella –> macrolides cover legionella

• OUTPATIENT
  
  • amoxcillin-clauvante + azithromycin/clarithromycin (macrolides)
  • doxycyline
  • resp. flouroquinilone
• INPATIENT
  
  • ceftriaxone/ceftaxime (IV)+ azithromycin
  • resp flouroquinilone

Question 9

outpatient tx of exacerbation COPD

Answer 9

similar to OM tx but,

1. must include for legionella –> macrolides: azithro_mycin,_ clarithromycin
2. oral 3rd gen cefs (cefdinir, cefpodox) not a good choice.

• amoxicillin-clauvanate + azithromycin/clarithromycin
• doxycyline
• resp. flouroquinilone

Question 10

inpatient tx for COPD exacerbation

Answer 10

3rd gen IV ceph + legionela coverage

• ceftriaxone/cefotaxamine + azithromycin
• resp flouroquinilone

Question 11

most common causes community aquired pneumonia (CAP)?

Answer 11

• viruses overall m/c
• bacteria
  
  • in adults: strep pneumonia
  • in chidlren: mycoplasma pneumonia

Question 12

outpatient tx of community acquired pneumonia (CAP)

Answer 12

for empiric coverage (i.e., knocking out all possible pneumonia agents if we dont know the exact cause)- give:

1. doxycyline, or
2. lefamulin, or
3. levofloxacin/moxifloacin

Question 13

outpatient tx for CAP if pt has already been Ab on 3 months?

Answer 13

• azithromycin + amoxicillin-clavulanate (1st choice)
• doxycyline + axmocillin-clavulanate
• lefamulin + amoxcillin-clavunate

next two choices given if pt has macrolide resistance > 20%

Question 14

inpatient treatment for CAP?

Answer 14

• ceftriaxone + azithromycin/doxycyline
  
  • doxy if macrolide resistance ? 2-
• lefamulin
• levofloxacin or moxifloxacin

Question 15

what ab can be used for both outpatient and inpatient CAP?

Answer 15

both:

• lefamulin
• levo/moxi - floxacin

outpatient only:

• doxycycline alone

inpatient only:

• doxycyline + ceftriazone
• azithromycin + ceftriazone

Question 16

what pneumonia Abs are contraindicated in pregnancy?

Answer 16

• doxycyline
• lefamulin
• levo,moxi - flxacin

Question 17

recommended Ab for CAP in pregnancy?

Answer 17

outpatient: amoxicillin-clavulanate + azithromycin

• same top choice as outpatient tx for 3-mos Ab use pt
• if penicclin allergy - replace amoxcilin w/ clindamycin

inpatient: ceftriaxone + azithromycin
* same top choice as any inpatient

cant use doxy, lefamulin, levo/moxi-floxacin

Question 18

tx for hospital aquired pneumonia (HAP)?

Answer 18

since HAP assumes MRSA infection:

ALL TREAMENTS involve vancomycin + an additional drug dependent on the risk of psuedomonas.

• no psueodmonas risk: vancomycin + ceftriaxone/ceftaxamine
• pseudomonas risk: vancomycin + piperacillin tazo/cefepime/levofloxacin
• MDR psueodmonas: vancomycin + meropenem + gentamycin/levofloxacin

Question 19

what can replace vancomycin in tx of hospital acquired pneumonia (HAP)?

Answer 19

linezolid

Question 20

in addition to vanc, what Ab is in every regimen for MDR psueodmonas HAP?

Answer 20

• meropenem (m for MDR)
  
  • can be replaed with imipenem

Question 21

what flouroquinilone does NOT cover psuedomonas?

Answer 21

moxifloxacin

Question 22

what carbapenems can NOT be for psuedomonas pneumonia?

Answer 22

• ertepenem - doesnt cover pseudomonas
• doripenem - absolutely C/I in all respiratory disease (esp pneumonia)

Question 23

treatment for ventilator associated pneumonia (VAP)?

Answer 23

VAP assumes MRSA AND assumes psueodmonas infection

• general peudomonas infection: vancomycin + cefepime/levofloxacin
• MRD: vancomycin + meropenem + gentamycin/levocloxacin

Question 24

tx of HAP pneumonia vs VAP pneumonia

Answer 24

similar, except:

1. vancomycin + 3rd gen ceph (ceftax, ceftriax) NOT an option for VAP, ,since VAP assumes psuedomonas and requires coverage
2. vancomycin + piperacillin tazobactam not an option for VAP

• VAP tx:
  
  • vancomycin + cefepime/levofloxacin (not MDR)
  • vancomycin + meropenem + gentamycin/levocloxacin (MDR)

Question 25

which B-lactams do NOT interact with probenacid?

Answer 25

* ceftriaxone * aztreonam

Question 26

important AEs of penicillins

Answer 26

* imipenem - seizurfes * aztreonam - neutropenia, thrombocytopenia

Question 27

vancomycin * MOA * coverage * how do bacteria become resistant to it/what drug to use in this case

Answer 27

* blocks PBP from transpeptidase reaction * coverage: gram + cocci incuding MRSA) * resistance: * terminal alinine it binds to mutated to serine/lysine * **use linezolid**

Question 28

vancomycin AEs and C/Is

Answer 28

* **red man syndrome** - avoid by pre-treating pt with _anti-histamine_ * **nephrotoxicity** * careful with vanc, diuretics

Question 29

aminoglycosides * MOA * coverage * key uses * AEs, C/I

Answer 29

* MOA: binds irreversibly to 30s subunit (bacteriacidal) * coverage: _gram -:_ *e. coli, klebsiella, psuedomonas* * use: to **"double cover" pseudomonas in** **HAP/VAP (gentamycin)** * ​i.e. for **MDR** as part of _vanc + meropenem_ regimen * nephrotoxicity * careful with vancomycin * C/I amphotericin, diuretics (furosemide) * otoxicity * C/I diruetics (furosemide)

Question 30

doxycyline * MOA * coverage * AE/CI

Answer 30

* MOA: reversibly bind to 30s subunit to block tRNA (bacteriostatic) * coverage: lots of shit plus weird pneumo - *mycoplasma pneumonia, clamydia pneumonia, legionella* * AE * GI * photosensitivty * CI * pregnancy

Question 31

macrolides AEs/drug drug interactions

Answer 31

AEs * GI problems * QT elongation drug-drug interactions: * clarithromycin: **CYP -3A4 inhibitor** --\> will increase plasma [] of CCBs, colchicine, statins, clindamycin * all macrolides: **LQT drugs** (Ia & III antiarrthmics, flouroquinilones)

Question 32

cindamycin * key uses * PK * AEs / drug drug interactions

Answer 32

* key use: * as a tx for CAP in pregnant women: clinda + azithromycin * as a backup for amoxicillin-clavulanate * PK - metabolized by CYP 3A4 * drug-drug interactions * CYP-3A4 inhibitors & inducers (CIVIK) * AE --\> **c. diff psuedomembrane colitis**

Question 33

linezolid * MOA * coverage * use * AEs * drug-drug interactions

Answer 33

* bind reversibly to 50s subunit (bacteriostatic) * coverage: gram + only * use: to replace vancomycin in tx in HAP & VAP * AEs: * _thrombocytopenia/ anemia_ * MOA/SSRI inhibition --\> * **hypertensive crisis** * **serotonin syndrome:** irritibitliary, seizures * drug-drug interactions: * SSRIs/MOA-I antidepressants * pseudophedrine

Question 34

what drugs cause prolonged QT interval?

Answer 34

* flouroquinilones * macrolides * lefamulin * televancin * Class Ia and III anti-arrhythmic

Question 35

what are the CYP-3A4 inducers?

Answer 35

* nafcillin * rifampin * carbamazepine

Question 36

CYP - 3A4 inhibitors

Answer 36

clarithromycin, isoniazid (TB dru, voriconazole, itraconizole ketoconiazole (CIVIK)

Question 37

lefamulin * MOA * PK * AE * drug drug

Answer 37

* inhibits peptidyl transferase (bacteriostatic) * PK * take \> 2 hrs before/after eating * metabolized by CYP-3A4 * AE * diarrhea * QT prolongation --\> torsades * drug drug interactions * other LQT drugs * CYP-3A4 inducers/inhibitors

Question 38

* flouroquinilones * MOA * PK * AEs/ drug-drug interactions

Answer 38

* bind to topiosomerase II (DNA gyrase) and IV (bactericidal) * PK - n/a * AEs * tendonitis/tendon rupture * aortic anurysm * gucose dysegulation * pseudomembranous colitis * QT elongation * CI: * **pregnancy** * **children \< 16** * drug drug interactions: * clindamycin - colitis risk * LQT drugs