Cystic Fibrosis

What is cystic fibrosis?

an incurable, hereditary disease that is caused by a mutation in the gene for the protein cystic fibrosis transmembrane conductance regulator (CFTR)

Where does the thick mucus caused by the gene mutation affect and what does it cause?

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

What is performed to confirm the diagnosis of cystic fibrosis?

a sweat test (sweat chloride test)

measurers the amount of salt (chloride) in the sweat, which is high in patients with CF

classic symptoms of CF

salty tasting skin, poor growth, poor weight gain, thick and sticky mucus production, frequent lung infections, coughing and shortness of breath

steatorrhea (fatty stools)

Correct order of inhaled medications for CF

1. inhaled bronchodilators (albuterol) to open the airways

2. hypertonic saline (HyerSal) to mobilize mucus to imrpove airway clearance

3. dornase alfa (Pulmozyme) to decrease viscosity of mucus to promote airway clearance (thins)

4. chest physiotherapy to mobilize mucus to improve airway clearance

5. inhaled antibiotics to control airway infection

What is the most common organism seen early in CF?

staphylococcus aurerus and haemophilus influenzae, followed by pseudomonas aeruginosa in adolecents and adults

What is recommended for infections caused by pseudomonas aeruginosa and why (for intermittent infection)?

two IV drugs

- aminoglycosides, beta lactams, quinolones

to provide potential synergy and prevent resistance

What is recommended for patients with chronic pseudomonas aeruginosa lung infections?

inhaled antibiotics to reduce bacterial burden

treatment is cycled with 28 days on therapy, followed by 28 days off

Why can a six month trial of oral azithromycin be considered for patients with chronic infection?

azithromycin has no direct bactericidal activity against pseudomonas, but disrupts biofilm formation by the bacteria which can improve lung function and decrease exacerbations

Pulmozyme generic

dornase alfa

How is hypertonic saline delivered?

via nebulizer (small ready to use vials)

How do you store dornase alfa?

store ampules in the refrigerator

protect from light

do not mix with any other drug in the nebulizer

tobramycin brand name

TOBI, TOBI podhaler (capsule for inhalation)

tobramycin side effects

ototoxicity

tinnitus

voice alteration

mouth and throat pain

tobramycin dosing cycle

give for 28 days, followed by 28 days off

dosed every 12 hours, but must be at least 6 hours apart

How to store TOBI, Bethkis, Kitabis (tobramycin solution for inhalation)?

regrigeration recommended (can be kept at room temperature for up to 28 days)

store in foil pouch to protect from light

do not mix with any other drug in nebulizer

How should TOBI podhaler (tobramycin capsule for inhalation) be stored?

store capsules at room temperature in a dry place

use with Podhaler device

do not swallow capsules

Aztronam brand

Cayston

Azetronam side effects

allergic reactions

bronchospasm

fever

wheezing

cough

chest discomfort

aztronam dosing

give for 28 days followed by 28 days off cycle

dosed every 8 hours, but must be at least 4 hours apart

How to store aztronam?

refrigeration recommended (can be kept at room temperature for up to 28 days)

do not mix with any other drug in the nebulizer

protect from light

Zithromax generic

azithromycin

azithromycin use in CF

to decrease exacerbations (oral)

pancrelipase brand

CREon

VikoACE

ZenPEP

(enzyme products)

Max dose for pancrelipase

all ages

<=10,000 units/kg/day

PEP warnings

colonic strictures

mucosal irritation

PEP side effects

abdominal pain

flatulence

nausea

What is pancreatic enzyme replacement for?

it helps patients with CF digest food, maintain weight, and improve nutrient absorption

Which PEP product must be given with a PPI?

Viokace

it is non-enteric coated

Can capsule PEP products be crushed or chewed?

No, DR capsules with enteric coating can be opened and sprinkled on soft, acidic foods like applesauce

avoid foods high pH such as dairy

(all other products besides Viokace tablet is a capsule)

What types of food should be avoided with delayed release capsules that can be opened?

foods high in pH such as dairy

Are PEP products interchangeable?

No, call prescriber for equivalent doses

Which PEP comes as a tablet?

Viokace (only PEP that is a tablet)

non-enteric coated

When should PEP be taken?

Taken before or with all meals and snacks

What types of meals may require higher doses of PEP?

high fat meals

What is the dose of PEP for snacks?

50% of mealtime dose

PEP storage instructions

protect from moisture

dispense in original container (except Zenpep and some Creon strengths)

do not refrigerate

Why must genotype testing be performed prior to initiation of cystic fibrosis transmembrane conductance regulator (CFTR) modulators?

because each drug is approved for very specific mutations

What is the most common mutation in the CFTR gene?

homozygous F508del mutation

Which CFTR modulator is not approved for use in homozygous f50del mutation?

Ivacaftor (Kalydeco)

Which CFTR modulators are approved for use in homozygous f50del mutation?

Lumacaftor/ivacaftor (Orkambi)

Tezacaftor/ivacaftor (Symdeko)

Which CFTR modulator is not approved for use in heterozygous f50del mutation?

elexacaftor/tezacaftor/ivacaftor (Trikafta)

How should CFTR modulators be taken?

with high-fat containing foods

What type of diet is recommended for CF patients?

high fact and calorically dense diet to help with nutrition, normal weight and growth, increased energy needs and to prolong survival

Which vitamin supplements are required for CF patients?

fat soluble vitamins A,D,E,K