Cystic Fibrosis Flashcards
an incurable, hereditary disease caused by a mutation in the gene for the protein cystic fibrosis transmembrane conduct regulator (CFTR)
CF
What does the CFTR mutation cause…
abnormal transport of ____,____and____ ions across the epithelium.. which causes?
abnormal transport of chloride, bicarbonate, and sodium ions across the epithelium, leading to think, viscous secretions affecting the lungs, pancreas, liver and intestines
–> difficulty breathing, lung infections, digestive complications
When are CF patients normally diagnosed? what age?
by age 2
If the initial screening identifies a risk of CF, then what test is performed?
a sweat chloride test, “sweat test”
confirms diagnosis - HIGH sodium in CF sweat
What are the classic symptoms of CF?
salty tasting skin, poor growth, and poor weight gain, coughing, SOB.
Patients experience obstruction of pancreatic ducts causing…
steatorrhea (fatty stools).
Malnutrition can result if CF is not treated
In CF, what is the first intervention (opens the airways)
inhaled bronchodilators (albuterol)
In CF, what is the second intervention (mobilizes mucus to improve airway clearance)
hypertonic saline (HyperSal)
In CF, what is the third intervention (decreases viscosity of mucus to promote airway clearance)
Dornase alfa (pulmozyme)
In CF, what is the fourth intervention (mobilizes mucus to improve airway clearance)
chest physiotherapy
In CF, what is the fifth and final intervention (controls airway infection)
inhaled antibiotics (targets p. aeruginosa)
The correct order of inhaled medication for CF is critical for…
to maximize absorption and effect
Do inhaled therapies have large systemic absorption?
no! minimal, small risk of toxicity
Impaired mucus clearance causes bacterial colonization and lung infections.
The most common organisms seen EARLY in the disease are:
staphylococcus aureus
H. influenzae
Which organism is commonly found in adolescents and adults?
Pseudomonas aeruginosa
What is characterized as an increase in cough, sputum production with change in sputum color (green), SOB and a rapid decline in FEV1
acute pulmonary exacerbations
How are infections caused by p aeruginosa treated?
2 IV antibiotics to provide synergy and prevent resistance, doses tend to be LARGER than normal
options: AG, beta lactase, quinolone and others that covers pseudomonas
For chronic infections, what is the recommended treatment for patients with pseudomonas lung infections?
inhaled antibiotics to reduce the bacterial burden; treatment is cycled with 28 days on, 28 days off
For chronic infections when a patient is receiving inhaled antibiotics, when should their bronchodilator/mucolytic be administered?
BEFORE antibiotics
Does azithromycin have direct bactericidal activity against pseudomonas?
no! but it disrupts biofilm formation by the bacteria which can improve lung function and decrease exacerbations
List airway clearance therapies (3)
1) bronchodilator (albuterol)
2) Hypertonic saline (HyperSal, PulmoSal) - nebulizer
3) Dornase alfa (Pulmozyme)
This drug works by degrading extracellular DNA in the lungs to decrease viscosity of thin mucus
Dornase alfa/ Pulmozyme
Which drug should NOT be mixed with any other drug in the nebulizer?
dornase alfa/ Pulmozyme
Which drug has to have the ampules stored in the fridge and need to be protected from light?
dornase alfa/ pulmozyme
List the inhaled antibiotics that target pseudomonas
1) tobramycin (TOBI, TOBI Podhaler)
2) aztreonam (Cayston)
3) azactam (IV) - acute
This drug’s side effect profile:
ototoxicity, tinnitus, voice alteration, mouth and throat pain
tobramycin INH
28 on, 28 off
tobramycin - this formulation recommends refrigeration, but can be kept at room temp for up to 28 days, but can’t be mixed with any other drug in the nebulizer
TOBI, bethkis, kitabis
tobramycin - this formulation has the capsules stored at room temp
TOBI Podhaler
q12 hours
These drug’s side effect profile: allergic reactions may be severe, bronchospasm, fever, wheezing, cough, chest discomfort
refrigeration recommended! do not mix with any other drug in the nebulizer
Aztreonam
azactam
28 on, 28 off
q8 hours
This oral drug is used off-label to decrease inflammation and decease exacerbations
azithromycin (Zithromax) PO
what do pancreatic enzyme products (PEPs) break down?
fat
starches
protein
this is a natural product harvested from porcine pancreatic glands which contains a combination of lipase, amylase, and protease
pancrelipase
PEPs are formulated to dissolve in the more BASIC pH where?
duodenum
How are PEPs dosed?
individualized for each patient based on the LIPASE component
dose is adjusted every 3-4 days until stools are normalized
Brand: Creon, Viokace, Zenpep
generic: pancrelipase
What is the max dose of Creon?
<10,000unit/kg/day
This drug has a warning for colonic strictures (rare, but higher risk once passed the max dose), can also cause mucosal irritation
side effects include abdominal pain, flatulance, nausea
Creon
Is creon interchangeable?
no!
Which PEP is a tablet? the only one; what must it be taken with?
(all others are capsules - want to be taken with acidic food, not dairy)
Viokace - it is non-enteric coached and MUST be given with a PPI
do you refrigerate PEPs?
no! but protect from moisture
Zenpep is not dispense in original container
This drug works by increasing the time the CFTR channels open, which enhances chloride transport activity
Ivacaftor (CFTR modulator)
> 6 months
substrate of CYP3A4…D/I!!
These drugs help correct the CFTR folding defect, which increases the amount of CFTR delivered to the cell surface
Lumacaftor, tezacaftor, elexavaftor (CFTR modulators)
Because each CFTR modulator is approved for very specific mutations, what must be performed prior to initiation?
genotype testing
What is the most common mutation in the CFTR gene?
homozygous F508del mutation
Orkambi>2y, Symdeko >6y, Trikafta >12y approved
What type of meal do you take CFTR modulators with?
high fat
What vitamin supplements are required for CF?
fat-soluble! ADEK for cellular function
Many patients with CF will eventually require…
insulin.. CF-related DM
