Cystic Fibrosis Flashcards
CF–>The Basics
1 in 3,000
Autosomal recessive genetic disease
Average life expectancy is 61 years
How is CF caused?
CF is caused by a mutation in a gene that encodes for the CFTR
Most common mutation is F508del
Newborn screen
Blood spot obtained from the infant is used to test for a variety of diseases
Positive test is not diagnostic
Early diagnosis and treatment of CF has increased patient weight and decreased hospitalizations
Diagnosis
One or more sign or symptom + evidence of CFTR dysfunction
Sweat chloride test
- pilocarpine iontophoresis
- > 60 mEq/L
Genetic testing
Pancreatic function
Kalydeco (ivacaftor)
CFTR potentiator: helps open gate to flow through and thin mucus
Age > or equal to 1 month
Kalydeco (ivacaftor) administration
Take with fatty foods
LFTs q3mo for 1 year then yearly
Baseline eye exam then yearly
Dose adjustment in hepatic impairment
CYP3A4 substrate
Approved for responsive mutations
Orkambi (ivacaftor/lumacaftor)
Age > or equal to 1 year
F508del homozygous: “helps door get to back of wall and ivacaftor helps open door”
Take with fatty foods
AST/ALT/Bil q3mo for 1 year, yearly
Baseline eye exam then yearly
Dose adjust in hepatic impairment
BIRTH CONTROL DRUG INTERACTION
Lumacaftor: CYP3A4 induce
Ivacaftor: CYP3A4 substrate
SE: SOB and chest tightness
Symdeko (tezacaftor/ivacaftor)
Age > or equal to 6
Approved for F508del/F508del or responsive mutation
Take with fatty food
AST/ALT/Bil q3mo for 1 year, yearly
Baseline eye exam then yearly
Dose adjust in liver disease
CYP3A4 substrate
Trikafta (Elexacaftor/tezacaftor/ivacaftor)
Age > or equal to 2
Approved for patients with at least one F508del
AST/ALT/Bil/Alk Phose qmonth for 6 months and then q3mo for 12 additional months then yearly
Baseline eye exam then yearly
Dose adjust in liver disease
Ivacaftor CYP3A4 substrate
If miss orange table by more than 6 hours take orange tablet when remember and skip even blue
Alyftrek (vanzacaftor/tezacaftor/deutivacaftor)
AST/ALT/Bil/Alk Phose qmonth for 6 months and then q3mo for 12 additional months then yearly
Baseline eye exam then yearly
Dose adjust in liver disease
Ivacaftor CYP3A4 substrate
Approved for if one F508del or another responsive mutation
Airway clearance
Recommended for all CF patients
No method proven better than another
Method based on patient
- manual airway clearance
- therapy vest
- flutter, acapella
- huff coughing
- meta neb
Dornase alfa
Maintenance lung treatment
MOA: reduces viscosity promoting clearance
Nebulized solution
Recommended in all CF patients > or equal to 6 years old; can use in select cases for < 6 years
Hypertonic Saline
Maintenance lung treatment
Nebulized solution that helps draw water into airway to clear mucus easier
Recommended in all CF patients > or equal to 6 years old; can use in select cases for < 6 years
Inhaled Mannitol
Maintenance lung treatment
18 years and older
Dry powder inhaler
Requires tolerance test prior
Alternative to hypertonic saline
SE: bronchospasm
Administer albuterol 5-15 minutes before
Anti-inflammatory
Azithromycin
<40kg 250mg MWF
>40kg 500mg MWF
Recommended in patients with chronic pseudomonas
Bronchodilator’s
Short acting beta agonist
Administer prior to inhaled hypertonic saline to decrease bronco constriction
CF exacerbation common pathogens
MSSA, MRSA
P. aeruginosa
H. influenza, klebsiella
E.coli
Stenotrophomonas maltophilia
Burkholderia
CF exacerbation empiric IV therapy
MRSA (only single coverage needed)
- Bactrim, linezolid, vancomycin, clindamycin, tetracycline
MSSA (only single coverage needed)
- Cefazolin, unasyn, coverage by anti-pseudomonal beta-lactam
CF exacerbation Pseudomonas for IV therapy
Double coverage
Zosyn
Primaxin
Ceftazidime
Meropenem
PLUS
Tobramycin/Amikacin
Beta-lactams altered kinetics
Increased renal and non-renal clearance
Max dose at shortest interval (q6-8h in hospital; q8h at home) or prolonged infusion
Aminogylcosides altered kinetics
Increased clearance and Vd (0.3 L/kg)
Initial dose 10-20 mg/kg/dose q24h
Inhaled Tobramycin
Recommended for initial pseudomonas eradication: One 28 day course
Suppression therapy in 28 days cycle for patients with chronic pseudomonas
3 positive cultures: 28 days on then 28 days off
Administration 15-20 minutes 300mg premade solution nebulizer
Podhaler 122mg = 4 capsules IH BID
Inhaled Aztreonam
Used in patients with chronic pseudomonas
Patients that cannot tolerate tobramycin
75mg IH TID
Pancreatic enzymes
500-2,500 units of lipase/kg per meal
Typically start with 1,000 units of lipase/kg per meal
Do not exceed 10,000 units of lipase/kg/day
Adjusted based on the number of stools per day fat content of stools, and growth/weight
Vitamin monitoring
Vitamin D: 25-OH–> goal > 30; preferred supplement (D3)
Vitamin A, E, K (PT ,INR)
CF related diabetes
Basal insulin
long acting insulin 0.25 units/kg starting dose
Diagnosis
fasting plasma glucose > or equal to 126 mg/dl
2 hour plasma glucose > or equal to 200 mg/dl
