55. Cystic Fibrosis

Question 1

T/F: Cystic fibrosis is a curable disease

Answer 1

False

Question 2

Cystic fibrosis is caused by a mutation in the gene for the protein _____ and this mutation causes abnormal transport of _____ ion across the epithelium, leading to thick, viscous secretions

Answer 2

Cystic fibrosis transmembrane conductance regulator (CFTR)
Chloride, bicarbonate, and sodium

Question 3

CF causes thick viscous secretions which affect ____, causing _____

Answer 3

the lungs, pancreas, liver, and intestines
causes difficulty breathing, lung infections, and digestive complications

Question 4

The avg life expectancy of a person with CF is ___ yo with more than 75% of pts being diagnosed by ___ yo

Answer 4

35-40
2 yo

Question 5

Dx of cystic fibrosis

Answer 5

Newborn screening first 2-3 days after baby is born
Initial screening identifies risk and then sweat chloride test (“sweat test”) is performed to confirm (looking for high salt (chloride) in sweat)

Question 6

S/sx of CF

Answer 6

salty tasting skin, poor growth and poor weight gain (despite adequate food intake), mucus production, frequent lung infections, coughing and SOB

Patients experience obstruction of pancreatic ducts causing steatorrhea (Fatty stools) and poor absorption of nutrients (including fat-soluble vitamins)

Clubbing of the fingers may be present

Question 7

____ and failure to thrive can result if CF is not treated

Answer 7

Malnutrition

Question 8

For treatment of lung complications from CF, correct order when administering inhaled medications is crucial to maximize absorption and effect. What is the order?

Answer 8

1) inhaled bronchodilators (e.g. albuterol) - opens the airway
2) Hypertonic saline (e.g. HyperSal) - mobilizes mucus to improve airway clearance
3) Dornase alfa (Pulmozyme) - decreases viscosity of (thins) mucus to promote airway clearance
4) Chest physiotherapy - mobilizes mucus to improve airway clearance
5) Inhaled abx - controls airway infection

Question 9

Inhaled therapies are the foundation of treatment in CF. The drug is delivered directly to the lungs, resulting in _____

Answer 9

minimal systemic absorption (reduces risk of toxicity)

Question 10

The most common organisms seen early in CF disease are ___ and ___, followed by ____ in adolescents and adults

Answer 10

Staphylococcus aureus
H. influenzae
Pseudomonas aeruginosa

Question 11

Acute pulmonary exacerbations are characterized by an increase in _____

Answer 11

cough, sputum production with change in sputum color (greenish), SOB, and a rapid decline in FEV1

Question 12

T/F: For intermittent infections caused by Pseudomonas, monothearpy aminoglycosides is recommended

Answer 12

False - 2 IV drugs are recommended potential synergy and prevent resistance

Includes aminoglycosides, beta-lactams, quinolones, and others that cover Pseudomonas aeruginosa

Question 13

When treating intermittent infection, IV abx doses tend to be (smaller/larger) than normal to address altered PK in pts with CF

Answer 13

larger

Question 14

What is the difference in abx use in intermittent vs chronic infection caused by psuedomonas CF?

Answer 14

Intermittent - 2 IV drugs
Chronic - inhaled abx, 28 days on and 28 days off

Question 15

Azithromycin does not cover pseudomonas but why is it used in cystic fibrosis?

Answer 15

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

Question 16

Dornase alfa (Pulmoyzme) storage notes

Answer 16

Store ampules in the refrigerator (do not expose to room temp ≥ 24 hrs)
Protect from light

Question 17

T/F: Dornase alfa (Pulmozyme) cannot be mixed with any other drug in the nebulizer

Answer 17

True

Question 18

What are inhaled abx used in CF lung infections?

Answer 18

Tobramycin (TOBI solution for inhalation, TOBI Podhaler capsule for inhalation)
Aztreonam (Cayston solution for inhalation)

Question 19

Side effects of tobramycin (TOBI, TOBI Podhaler, Bethkis, Kitabis Pak)

Answer 19

Ototoxocity, tinnitus, voice alteration, mouth/throat pain, dizziness, bronchospasm

Question 20

Tobramycin (TOBI, TOBI Podhaler, Bethkis, Kitabis Pak) dosing schedule

Answer 20

On + off cycle (28 days on, 28 days off)
Dosed every 12 hrs, must be at least 6 hrs apart

Question 21

Tobramycin (TOBI, TOBI Podhaler, Bethkis, Kitabis Pak) storage notes

Answer 21

TOBI, Bethkis, Kitabis: refrigeration recommended (can be kept at room temp up to 28 days); protect from light; do not mix with any other drug in nebulizer
TOBI Podhlaer: room temp in dry place; use with Podhaler device; do NOT swallow capsules

Question 22

T/F: Tobramycin Podhaler capsules can be PO or nebulized in a special Podhaler device

Answer 22

Flase - do NOT swallow capsules, nebulizer only

Question 23

Inhaled Aztreonam (Cayston) side effects

Answer 23

Allergic reactions (may be severe), bronchospasm, fever, wheezing, cough, chest discomfort

Question 24

Inhaled Aztreonam (Cayston) dosing schedule

Answer 24

On + off cycle (28 days on, 28 days off)
Dosed every 8 hrs but must be at least 4 hrs apart

Question 25

Inhaled Aztreonam (Cayston) storage notes

Answer 25

Refrigeration recommended, can be kept at room temp up to 28 days Protect from light Use with Altera nebulizer system

Question 26

Why do most CF patients supplement their diet with pancreatic enzyme products (PEPs)?

Answer 26

Thick mucus in CF obstructs pancreatic enzyme flow, resulting in a lack of these enzymes reaching the GI tract and subsequent malabsorption (causes smelly greasy/oily stools) PEPs help break down fat, starches, and protein

Question 27

Pancrelipase is a natural produce harvested from ____ which contains a combination of _____

Answer 27

Porcine pancreatic glands Lipase, amylase, and protease

Question 28

PEPs are formulated to dissolve in the more basic pH of ___

Answer 28

duodenum

Question 29

PEP is individualized for each pt and based on the ___ component

Answer 29

Lipase

Question 30

PEP dosing is adjusted every ___ until stools are normalized

Answer 30

3-4 days

Question 31

Max dosing of pancrelipase

Answer 31

Lipase ≤2500 units/kg/meal or ≤10,000 units/kg/day Note: Doses >6,000 units/kg/meal are a/w colonic stricture

Question 32

What are some examples of pancrelipase products

Answer 32

Creon Viokace Zenpep

Question 33

Warnings pancrelipase

Answer 33

Fibrosing colonopathy advancing to colonic strictures (rare, higher risk with doses >10,000 lipase units/kg/day), mucosal irritation, hyperuricemia

Question 34

Side effects pancrelipase

Answer 34

Abdominal pain, flatulence, nausea, HA, neck pain

Question 35

Most PEP formulation is capsules. Which PEP formulation is the only PEP that is a tablet (non-enteric coated) and requires PPI?

Answer 35

Viokace

Question 36

T/F: PEP formulations are not interchangeable

Answer 36

True

Question 37

PEP administration timing

Answer 37

before or with all meals and snacks High fat meals may require higher doses Use 50% of mealtime dose with snacks

Question 38

Can PEP capsules be opened to be sprinkled on soft food?

Answer 38

DR capsules with enteric coated microspheres/microtablets may be opened and sprinkled on soft, acidic foods (pH≤4.5) like applesauce Avoid foods with high pH such as dairy Note: do not retain capsule contents in mouth, swallow immediately with water to avoid mucosal irritation and stomatitis

Question 39

PEP should be dispensed in original container except ___

Answer 39

Zenpep and some Creon strengths

Question 40

The most common mutation in CFTR gene is ____

Answer 40

homozygous F508del mutation (2 copies of the same allele)

Question 41

Which CFTR modulators are approved for homozygous F508del mutation+additional responsive mutations?

Answer 41

Lumacaftor/ivacaftor (Orkambi) Tezacaftor/ivacaftor (Symdeko)

Question 42

Which CFTR modulators are approved for heterozygous F508del mutation+additional responsive mutations??

Answer 42

Elexacaftor/tezacaftor/ivacaftor (Triakfta)

Question 43

Which CFTR modulators are NOT approved for homozygous F508del mutation but approved for use in other responsive mutations?

Answer 43

Ivacaftor (Kalydeco)

Question 44

Ivacaftor MOA

Answer 44

Increasing the time the CFTR channels remain open = enhances chloride transport activity

Question 45

Lumacaftor, tezacaftor, elexacaftor MOA

Answer 45

Help correct CFTR folding defect, which increases the amount of CFTR dilvered to the cell surface

Question 46

What type of diet is recommended to help with nutrition, normal weight and growth, increased energy needs and to prolong survival?

Answer 46

High fat and calorically dense diet

Question 47

What vitamin supplements are required for CF patients?

Answer 47

Fat-solute vitamins A, D, E, and K

Question 48

T/F: many pts with CF will eventually require metformin for treatment of CF-related DM

Answer 48

False - insulin