Chapter 55: Cystic Fibrosis Flashcards
What mutation causes cystic fibrosis
cystic fibrosis transmembrane conductance regulator (CFTR)
The mutation for CF causes
abnormal transport of chloride, bicarb, and sodium ions across the epithelium, leading to thick, viscous secretions which affects the lungs, pancreas, liver and intestines
Most patients are diagnosed with CF by what age
2 years
What is used to determine a CF diagnosis
Sweat test
high amount of chloride in CF patients
Classic symptoms of CF
salty tasting skin, poor growth and poor weight gain, coughing and SOB, frequent infections
Patients with CF experience obstruction of pancreatic ducts, causing _____ and poor absorption of nutrients, including fat-soluble vitamins
steatorrhea (fatty stools)
What is the correct order to administer medications for CF
- inhaled bronchodilators (e.g., albuterol) - opens airways
- Hypertonic saline (e.g., HyperSal) - mobilizes mucus
- Dornase alfa (Pulmozyme) - thins mucus to promote airway clearance
- Chest physiotherapy - mobilizes mucus to improve airway clearance
- Inhaled antibiotics - controls airway infection
correct order critical to maximize absorption
Most common organisms seen early in CF
Staph aureus & H. influenzae, followed by PSA in adolescents and adults
Treatment for intermittent infections in CF caused by pseudomonas
2 IV drugs to provide potential synergy and prevent resistance
- aminoglycosides, BL, quinolones, and others that cover pseudomonas
doses larger tha normal to address altered PK in CF patients
What is recommended for patients with chronic pseudomonas lung infections to reduce the bacterial burden
Inhaled antibiotics
How are inhaled antibiotics used in chronic PSA lung infections for CF
cycled with 28 days on therapy and 28 days off
Which antibiotic can be considered for patients with chronic infection who are worsening on conventional treatment to decrease inflammation and exacerbations
Azithromycin (has no direct activity against pseudomonas but can be used to disrupt biofilms)
How is hypertonic saline administered
via nebulizer
Dornase alfa brand name
Pulmozyme
T/F: dornase alfa can be mixed with other drugs in a nebulizer
false
Which medication thins mucus
dornase alfa
decreases viscosity of mucus
Where should dornase alfa ampules be stored ___ and protected ____
in the refrigerator
and protected from light
think of keeping them in the refrigerator door
Which inhaled antibiotics are used to target pseudomonas
Tobramycin, aztreonam, azactam
Tobramycin brand name
TOBI, TOBI Podhaler (capsule for inhalation)
Side effects of inhaled tobramycin
ototoxicity, tinnitus, voice alterations, mouth & throat pain
Tobramycin inhaled doses must be at least ___ hrs apart
6
Aztreonam and Azactam inhaled doses must be at least ___ hrs apart
4
remember the As look like 4
TOBI, Bethkis, and Kitabis are recommended to be kept refrigerated, but can be kept at room temp up to __ days
28
T/F: TOBI, Bethkis, and Kitabis can be mixed with other meds in the nebulizer
False
TOBI podhaler must be kept
at room temp
Side effects of inhaled Aztreonam and Azactam
allergic reactions (may be severe), bronchospasm, fever, wheezing, cough, chest discomfort
Aztreonam and Azactam are recommended to be kept refrigerated, but can be kept at room temp up to __ days
28
T/F: Aztreonam and Azactam can be mixed with other meds in the nebulizer
false
____ is a natural product harvested from porcine pancreatic glands which contains a combination of lipase, amylase and protease
Pancrelipase
Pancreatic enzyme products (PEPs) are formulated to dissolve in the more (acidic/basic) pH of the duodenum
basic
The dose of pancrelipase is ____ for each patient and is based on the ____ component
individualized
lipase
Once PEP therapy is started, the dose is adjusted every 3-4 days until
stools are normalized
Pancrelipase brand names
Creon - (remember: panCRElipase)
Zenpep - (remember PEP)
Viokace - (remember ending ACE)
Max dose for all ages of pancrelipase
≤ 10,000 units/kg/day
Pancrelipase warnings
fibrosing colonopathy advancing to colonic strictures, mucosal irritation
Pancrelipase side effects
abdominal pain, flatulence, nausea
What is the purpose of pancreatic enzyme replacement in CF
helps digest food, maintain weight and improve nutrient absorption
T/F: PEP formulations are interchangeable
false
Which PEP comes as a tablet
Viokace
Viokace must be given with
a PPI (it is not enteric coated)
Which PEPs come as capsules
Creon and Zenpep
When should PEPs be taken
before or with all meals and snacks
How much of the PEP dose should be taken with snacks
50% of the mealtime dose
Ivacaftor MOA
increases the time the CFTR channels remain open, which enhances chloride transport activity
Lumacaftor, tezacaftor and elexacaftor MOA
help correct the CFTR folding deficit, which increases the amount of CFTR delivered to the cell surface
What must be performed prior to initiation of CFTR modulators
genotype testing
The most common mutation in the CFTR gene is a homozygous ____ mutation
F508del
Ivacaftor is not approved for which mutation?
F508del homozygous
Which drugs are approved for use in the homozygous F508del mutation
Lumacaftor/ivacaftor
tezacaftor/ivacaftor
elexacaftor/tezacaftor/ivacaftor
How should CFTR modulators be taken
with high-fat containing food
