Cystic Fibrosis

Question 1

what is the order of therapy initiation in CF

Answer 1

inhaled bronchodilators
hypertonic saline
dornase alfa
chest physiotherapy
inhaled ABX

Question 2

hypertonic saline MOA in CF

Answer 2

mobilizes mucous and increases airway clearence

Question 3

dornase alfa MOA in CF

Answer 3

decreases mucus viscosity

Question 4

what pathogens typically cause infxn in CF

Answer 4

pseud!
s aureus
h inf

Question 5

how is dosing of ABX different in pseud? why?

Answer 5

doses are usually higher to account for altered kinetics in CF patients, penetrate lung tissue and account for resistance

Question 6

what ABX are common in CF exacerbations

Answer 6

tobramycin
aztreonam
azithromycin

Question 7

bronchodilators and mucolytics should be given before or after ABX in CF?

Answer 7

before!

Question 8

tobramycin dosing

Answer 8

TOBI (soln for neb) = 300mg neb Q12H
TOBI Podhaler (cap for neb) = 112mg (4x28mg caps) Q12H

28d on and 28d off cycle

Question 9

side effects of tobramycin to warn patients about

Answer 9

tinnitus
ototoxicity
voice alteration
dizziness
mouth and throat pain

Question 10

if a patient does not want to wake up in the night to take a second dose of tobramycin, what is the soonest they can take the second dose?

Answer 10

6 hours apart

Question 11

tobramycin is for use in _____ yo

Answer 11

6+ yo

Question 12

aztreonam dosing CF

Answer 12

75mg neb TID
28d on and 28d off cycle

Question 13

if a patient does not want to wake up in the night to take an aztreonam 75mg dose via neb, when is the soonest they can take it after the previous dose?

Answer 13

4 hours apart

Question 14

aztreonam is for use in ____ yo

Answer 14

7+

Question 15

aztreonam is stable at room temp for ____

Answer 15

28 days

Question 16

side effects to warn patients about with aztreonam use

Answer 16

serious allergic reaction, bronchospasm, fever, wheezing, cough, chest discomfort

Question 17

azithromycin dosing in CF

Answer 17

<40kg: 250mg TIW
40+kg: 500mg TIW

Question 18

what is the function of azithromycin in CF

Answer 18

has no bacteriocidal activity in CF

disrupts biofilm formation by bacteria which can improve lung function and decrease exacerbations

Question 19

patient is a 6 yo male (22.7kg, 50lb) with a new CF dx. What should the patient be started on?
CF is heterozygous for the F508del mutation

Answer 19

albuterol prn
candidate for Trikafta
should initiate pancreatic enzymes (patient is over 4 yo so should receive 500U lipase/kg/meal and 50% of that as snacks)
mealtime dose = 11,350 U lipase
snack dose = 5,675 U lipase

round depending on brand used

Question 20

if a patient is already on albuterol and hypertonic saline, what is the next recommended addition to therapy

Answer 20

dornase alfa

Question 21

dornase alfa
brand
dosing
MOA

Answer 21

Pulmozyme
2.5mg daily w neb
decreases mucus viscocity

Question 22

pancreatic enzyme dosing

Answer 22

<4 yo: 1,000 U lipase/kg/meal
4+ yo: 500 U lipase/kg/meal

Question 23

what is the max dose of lipase per meal? per day?

Answer 23

max 2,500 U/kg/meal
max 10,000 U/kg/day

Question 24

pearls for pancreatic enzyme admin

Answer 24

can sprinkle cap
keep good fluid intake
brands are not interchangeable
no dairy

Question 25

CFTR modulators for homozygous F508del

Answer 25

Orkambi (lmacaftor/ivacaftor)
Syndeko (tezacaftor/ivacaftor)

Question 26

CFTR modulator for heterozygous F508del

Answer 26

Trikafta (elexacaftor/tezacaftor/ivacaftor)

Question 27

what are the diet concerns and or recommendations in CF

Answer 27

high fat and high calorie diet
ADEK supplements needed
may require insulin for CF-related DM