Cystic Fibrooooo

Question 1

How old do you have to be to use ivacaftor?

Answer 1

older than 1 month

Question 2

How old do you have to be to use Lumacaftor-Ivacaftor

Answer 2

Older than 1 year

Question 3

How old do you have to be to use tezacaftor/ivacaftor

Answer 3

older than 6 years

Question 4

How old do you have to be to use elexacaftor/tezacaftor/ivacaftor

Answer 4

Older than 2 years

Question 5

Mutation that can use ivacaftor

Answer 5

ivacaftor-responsive CFTR mutation (G551D) - I think we get this chart on the exam??

Question 6

Mutation that can use lumacaftor/ivacaftor

Answer 6

2 copies of the F508 del CFTR mutation (homozygous)

Question 7

Mutation that can use tezacaftor/ivacaftor

Answer 7

2 copies of the F508 del CFTR mutation (homozygous)

OR

> 1 CFTR mutation that is reponsive to T-I

Question 8

Mutation that can use elexacaftor/tezacaftor/ivacaftor

Answer 8

Everyone :)

Question 9

ivacaftor MOA

Answer 9

• Facilitate opening of the Cl channel (CFTR potentiator)
• Does NOT create more protein, helps existing proteins work better

Question 10

lumacaftor MOA

Answer 10

fixes defective CFTR protein so that it can move to the proper place on the airway cell surface (CFTR corrector)

Question 11

tezacaftor MOA

Answer 11

fixes defective CFTR protein so that it can move to the proper place on the airway cell surface (CFTR corrector)

Question 12

CFTR modulator agents

Answer 12

-caftor

Question 13

CFTR modulator monitoring

Answer 13

• AST/ALT Q3mo. for the first year and then annualy after
  
  • Need dose adjustment if liver impairment

Question 14

CFTR admin

Answer 14

• Give with fat containing meal to boost absoprtion
  
  • NO GRAPEFRUIT

Question 15

Dornase alfa in CF

Answer 15

• Breaks up secretions
• Improves pulmonary function and reduce acute pulmonary exacerbations
• Well tolerated

Question 16

Hypertonic salinein CF

Answer 16

• Doesn’t improve lung function but does reduce times that pateint gets sick
• Well tolerated, but some bronchospasm reported as AE

Question 17

Bronchodilator use in CF

Answer 17

• Really only used because some of the other meds can cause bronchospasms (e.g. hypertonic saline
• Albuterol is the most used agent

Question 18

anti-inflammatory agent in CF

Answer 18

Azithromycin - not being used as an ABX
- Dosed MWF
- If pt <25kg: 10mg/kg
- If pt <40kg: 250mg
- If pt >40kg: 500mg

Question 19

Azithromycin indication in CF?

Answer 19

most clear indication for patients w PA colonization
Can be used w/o PA if hx of frequent APEs

Question 20

CF non-pharm and supplements

Answer 20

• Flu vaccine
• Physiotherapy
• Vitamins: A, D, E, K
• Pancreatic enzyme replacement (PERT) - microencapsulated products
  - dose dependent on lipase component
• Fe
• Zinc if poor weight gain

Question 21

CF inhaled ABX

Answer 21

• Tobramycin
  
  • Nebulizer admined over 15min
  • DPI admined over 2-7 min
• Aztreonam
  
  • Nebulizer admined over 2-3 min
• Use ABX alternating 28 days ON and 28 days OFF → reduce resistnace

Question 22

S/S of acute CF pulmonary exacerbation

Answer 22

• Cough, Increased sputum production
• SOB
• Chest pain
• Loss of appetite, Weight loss
• Lung function decline

Question 23

CF exacerbation admission: what to do with homes meds

Answer 23

basically double frequency
- Increase vest treatment frequency
- Increase dornase alfa frequency
- Infrease hypertonic saline frequency
- Increase bronchodilator frequency

doubleitandgiveittothenextperson

Question 24

CF exacerbation admission: ABX monitoring

Answer 24

• S/S persistence and/or resolution
• Pulmonary function tests: FEV1 and FVC
• Sputum culture and susceptibilities
• BUN/SCr
• ABX serum [ ]
  if no improvement in 5-7 days, re-culture and/or adjust ABX (

Question 25

CF exacerbation: MSSA infection ABX options

Answer 25

anti-staph penicillin OR cephalosporin 10-14D

Question 26

CF exacerbation: MSSA and PA infection ABX options

Answer 26

Aminoglycoside AND cefepime 10-14D

Question 27

CF exacerbation: MRSA infection ABX options

Answer 27

Vanco or linezolid 10-14D

Question 28

CF exacerbation: MRSA and PA infection ABX options

Answer 28

- vanco or linezolid + - aminoglycoside + - beta-lactam (ceftazidime) for 10-14D

Question 29

Aminoglycoside goal [ ]

Answer 29

- Traditional - Goal peak: 10-12 mcg/ml - Goal trough: <1.5 mcg/ml - Extended interval - Goal peak: 22.5-27.5 mcg/ml - Goal 18hr: <1mcg/ml - AUC 80-100 mcg/ml*hr

Question 30

Vanco goal [ ]

Answer 30

- Goal trough: 10-20 mcg/mL (→ AUC/MIC >400) - Serum concentrations drawn initially and then every 3 – 7d

Question 31

CFTR modulator AE

Answer 31

Generally well tolerated, but.... - abdominal pain - diarrhea - rash - rhinorrhea - headache - elevated ALT/AST

Question 32

How is ivacaftor dosed?

Answer 32

- BID - strength dependent on age and weight

Question 33

How is lumacaftor/ivacaftor dosed

Answer 33

- combo tab BID - strength dependent on age and weight

Question 34

How is tezacaftor/ivacaftor dosed

Answer 34

- combo tab in AM, ivacaftor tab in PM - strength dependent on age and weight

Question 35

How is elexacaftor/tezacaftor/ivacaftor dosed?

Answer 35

- combo tab in AM and ivacaftor in PM - strength dependent on age and weight

Question 36

CFTR modulator DDI with moderate CYP3A4 inhibitors

Answer 36

erythromycin and fluconazole - iva: decrease to QD - teza or tri: combo and iva taken on alternating days

Question 37

CFTR modulator DDI with **strong** CYP3A4 inhibitors

Answer 37

clarithromycin and itraconazole - iva: decrease to twice weekly - teza or tri: decrease to twice weekly - luma: decrease dose to 1 tab QD for 1 week then return back to BID (*only if luma is being added to strong CYP3A4, not if CYP3A4 being added to luma*

Question 38

CFTR modulator DDI with CYP3A4 **inducers**

Answer 38

rifampi, CBZ, phenobarbital, phenytoin, St. John - avoid CFTR use

Question 39

When to use ETI

Answer 39

First line, whenever applicable in whoever can

Question 40

When to use TI

Answer 40

In patients who have the appropriate mutation, can't use ETI and are over 6

Question 41

When to use iva

Answer 41

if pt < 2 years but greater than 1 month old and has appropriate mutation; switch to ETI when they turn 2

Question 42

When to use LI

Answer 42

if pt < 2 years but greater than 1 year and is F508delta homo * switch to ETI when they turn 2

Question 43

Important equations for CF ABX | there's 3: Ke, C, and T1/2

Answer 43

- Ke = ln(C1/C2) / ∆t - C = C0 (e^-kt) - T1/2 = 0.693/ Ke | AGS peak is 1 hr post infusion

Question 44

The patient develops an erythematous, pruritic rash on her face, neck, and upper torso, during vancomycin infusion. What is it?

Answer 44

AnaphyLACTOID reaction - vanco flushing syndrome (mast cell mediated but not hypersensitivity)

Question 45

How to treat vanco anaphylactoid reaction?

Answer 45

Step 1: Stop vancomycin infusion Step 2: Order diphenhydramine +/- H2RA +/- IV fluids (if patient hypotensive) Most episodes will resolve within 20 minutes, and the vancomycin may be restarted at 50% of the original rate (mild cases)

Question 46

What do you do if Scr increases 50% while on abx therapy for APE?

Answer 46

Check tobramycin 18-hour level and vancomycin trough prior to next dose. Hold doses pending level assessment.