Chapter 55: Cystic Fibrosis

Question 1

What mutation causes cystic fibrosis?

Answer 1

cystic fibrosis transmembrane conductance regulator (CFTR)

Question 2

What does the mutation for CF cause?

Answer 2

abnormal transport of chloride, bicarb, and sodium ions across the epithelium, leading to thick, viscous secretions which affects the lungs, pancreas, liver and intestines

Question 3

Most patients are diagnosed with CF by what age?

Answer 3

2 years

Question 4

What is used to determine a CF diagnosis?

Answer 4

Sweat test

Question 5

What are the classic symptoms of CF?

Answer 5

Salty tasting skin, poor growth and poor weight gain, coughing and SOB

Question 6

What do patients with CF experience due to obstruction of pancreatic ducts?

Answer 6

Steatorrhea (fatty stools)

Question 7

Most common organisms seen early in CF

Answer 7

Staph aureus & H. influenzae, followed by PSA in adolescents and adults

Question 8

What is the treatment for intermittent infections in CF caused by PSA?

Answer 8

2 IV drugs to provide potential synergy and prevent resistance.

Question 9

What types of drugs are used to cover PSA?

Answer 9

Aminoglycosides, beta-lactams (BL), quinolones, and others.

Question 10

What is the first step in administering medications for CF?

Answer 10

Inhaled bronchodilators (e.g., albuterol) - opens airways

Question 11

What is the second step in administering medications for CF?

Answer 11

Hypertonic saline (e.g., HyperSal) - mobilizes mucus

Question 12

What is the third step in administering medications for CF?

Answer 12

Dornase alfa (Pulmozyme) - thins mucus to promote airway clearance

Question 13

What is the fourth step in administering medications for CF?

Answer 13

Chest physiotherapy - mobilizes mucus to improve airway clearance

Question 14

What is the fifth step in administering medications for CF?

Answer 14

Inhaled antibiotics - controls airway infection

Question 15

What is recommended for patients with chronic PSA lung infections to reduce the bacterial burden?

Answer 15

Inhaled antibiotics

Question 16

How are inhaled antibiotics used in chronic PSA lung infections for CF?

Answer 16

Inhaled antibiotics are cycled with 28 days on therapy and 28 days off.

Question 17

Which antibiotic can be considered for patients with chronic infection who are worsening on conventional treatment to decrease inflammation and exacerbations

Answer 17

Azithromycin (has no direct bactericidal activity against PSA)

Question 18

How is hypertonic saline administered?

Answer 18

via nebulizer

Question 19

What is the brand name of Dornase alfa?

Answer 19

Pulmozyme

Question 20

True or False: dornase alfa can be mixed with other drugs in a nebulizer.

Answer 20

false

Question 21

Storage requirements for Dornase alfa

Answer 21

store ampules in the refrigerator and protect from light

Question 22

Which medication thins mucus?

Answer 22

dornase alfa

Question 23

Which inhaled antibiotics are used to target PSA?

Answer 23

Tobramycin, aztreonam, azactam

Question 24

What is the brand name of Tobramycin?

Answer 24

TOBI, TOBI Podhaler (capsule for inhalation)

Question 25

What are the side effects of inhaled tobramycin?

Answer 25

Ototoxicity, tinnitus, voice alterations, mouth & throat pain

Question 26

What is the minimum time interval between inhaled tobramycin doses?

Answer 26

6 hours

Question 27

What is the minimum time interval between inhaled aztreonam (Azactam) doses?

Answer 27

4 hours

Question 28

What is the recommended storage condition for TOBI, Bethkis, and Kitabis?

Answer 28

They are recommended to be kept refrigerated.

Question 29

How long can TOBI, Bethkis, and Kitabis be kept at room temperature?

Answer 29

They can be kept at room temperature for up to 28 days.

Question 30

What are the side effects of inhaled Aztreonam?

Answer 30

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

Question 31

What severe allergic reactions can occur with Azactam?

Answer 31

Severe allergic reactions may occur.

Question 32

What is a natural product harvested from porcine pancreatic glands that contains a combination of lipase, amylase, and protease?

Answer 32

Pancrelipase

Question 33

Pancreatic enzyme products (PEPs) are formulated to dissolve in the more acidic or basic pH of the duodenum?

Answer 33

basic

Question 34

The dose of pancrelipase is individualized for each patient and is based on which component?

Answer 34

lipase

Question 35

How often is the dose of PEP therapy adjusted?

Answer 35

Every 3-4 days until stools are normalized

Question 36

What are the brand names of Pacrelipase?

Answer 36

Creon, Zenpep, Viokace

Question 37

What is the maximum dose of pancrelipase for all ages?

Answer 37

< / = 10,000 units/kg/day

Question 38

What are the warnings associated with pacrelipase?

Answer 38

Fibrosing colonopathy advancing to colonic strictures, mucosal irritation

Question 39

What are the side effects of Pacrelipase?

Answer 39

Abdominal pain, flatulence, nausea

Question 40

What is the purpose of pancreatic enzyme replacement in CF?

Answer 40

Helps digest food, maintain weight and improve nutrient absorption.

Question 41

True or False: PEP formulations are not interchangeable.

Answer 41

True.

Question 42

Which PEP comes as a tablet?

Answer 42

Viokace.

Question 43

What must Viokace be given with?

Answer 43

A PPI (it is not enteric coated)

Question 44

Which PEPs come as capsules?

Answer 44

Creon and Zenpep

Question 45

When should PEPs be taken?

Answer 45

Before or with all meals and snacks

Question 46

How much of the PEP dose should be taken with snacks?

Answer 46

50% of the mealtime dose

Question 47

What is the mechanism of action (MOA) of Ivacaftor?

Answer 47

Ivacaftor increases the time the CFTR channels remain open, which enhances chloride transport activity.

Question 48

What is the MOA of Lumacaftor, tezacaftor, and elexacaftor?

Answer 48

They help correct the CFTR folding deficit, which increases the amount of CFTR delivered to the cell surface.

Question 49

What is the most common mutation in the CFTR gene?

Answer 49

The most common mutation is a homozygous **F508del** mutation.

Question 50

How should CFTR modulators be taken?

Answer 50

With high-fat containing food

Question 51

Which drugs are approved for use in the homozygous F508del mutation

Answer 51

Lumacaftor/ivacaftor tezacaftor/ivacaftor elexacaftor/tezacaftor/ivacaftor