Cystic Fibrosis Flashcards
What is cystic fibrosis (CF)?
- CF is an incurable, hereditary disease caused by a mutation in the gene for protein cystic fibrosis transmembrane conductance regulator (CFTR)
- The average life expectancy is 35-40 years with most of the patients being diagnosed by 2 years of age
What does the mutation of CF causes?
- Abnormal transport of chloride, bicarbonate and sodium ions across the epithelium, leading to thick, viscous secretions
- The thick mucus affects the lungs, pancreas, liver and intestines, which causes difficulty breathing, lung infections and digestive complications
How do you diagnose CF?
- Newborn screening is performed in the first 2-3 days after a baby is born. If it identifies a risk of CF, then a sweat chloride test (“sweat test”) is performed
What are the signs and symptoms of CF?
- Salty tasting skin
- Poor growth
- Poor weight gain
- Mucus production
- Frequent lung infections
- Coughing and SOB
- Steatorrhea (fatty stools)
- Malnutritions (if CF is not treated)
How do you reduce lung complications in CF?
- Administering inhaled medications in the correct order is critical to maximize absorption and effect
- Airway clearance therapies are given before inhaled antibiotics
- Inhaled medications are delivered directly to the lungs, resulting in minimal systemic absorption (reducing the risk of toxicity)
List the inhaled medications used to reduce the lung complications in order and their purpose
- Inhaled bronchodilators (e.g., albuterol) - Opens the airways
- Hypertonic saline (e.g., HyperSal) - Mobilizes mucus to improve airway clearance
- Dornase alfa (Pulmozyme) - Decreases viscosity of (thins) mucus to promote airway clearance
- Chest physiotherapy - Mobilizes mucus to improve airway clearance
- Inhaled antibiotics - Controls airway infection
Most patients will require oral medications (e.g., pancreatic enzyme products, azithromycin). These can be given at any time
Which organisms cause intermittent infection?
- Early in the disease: Staphylococcus aureus and Haemophilus influenzae
- Adolescents and adults: Pseudomonas aeruginosa
How is acute pulmonary exacerbations characterized?
- Increase in cough, sputum production with a greenish sputum, SOB and decline in FEV1
What medications are recommended for infections caused by Pseudomonas aeruginosa? And why?
- Two IV drugs are recommended to provide potential synergy and prevent resistance
- These include aminoglycosides
- Doses tend to be larger than normal to address altered pharmacokinetics
How is chronic infection treated in CF?
- Inhaled antibiotics are recommended for patients with chronic Pseudomonas aeruginosa infections
- Treatment is cycled with 28 days on therapy, followed by 28 days off
- If a patient is using a bronchodilator and/or mucolytic, these should be given prior to the antibiotic inhalation
When to consider initiating azithromycin treatment? How does it work?
- A 6 month azithromycin trial can be considered for patients with chronic infection who are worsening on conventional treatment
- Azithromycin has no direct activity against Pseudomonas but it disrupts biofilm formation by the bacteria which can improve lung fx and decrease exacerbations
List airway clearance therapies and their drug effects
1) Bronchodilator (e.g., albuterol)
2) Hypertonic saline (HyperSal, PulmoSal)
* Delivered via a nebulizer
3) Dornase alpha (Pulmozyme)
* Decrease viscosity (thins) mucus
* Store ampules in the refrigerator
* Protect from light
* Do not mix with any other drug in the nebulizer
ALL INHALED
List inhaled antibiotics and their drug effects
Inhalation form to target Pseudomonas aeruginosa colonization to decrease infections/hospitalization
1) Tobramycin (TOBI, TOBI Podhaler)
* Solution for inhalation: all (except TOBI Podhaler) - 300 mg via nebulizer Q12H
- Capsule for inhalation: TOBI Podhaler - 112 mg (4 x 28 mg caps) via inhalation Q12H
- SEs: ototoxicity, tinnitus, voice alteration, mouth and throat pain
- Give 28 days, followed by 28 days off
- Doses must be 6 hours apart
- TOBI, Bethkis, Kitabis: refrigeration recommended (can be kept at room temperature up to 28 days), do not mix with any other drug in the nebulizer
- TOBI Podhaler: store capsules at room temperature, do not swallow capsules
2) Aztreonam and Azactam
* SEs: allergic reactions (maybe severe), bronchospasm, fever, wheezing, cough, chest discomfort
- Give for 28 days, followed by 28 days off
- Doses must be 4 hours apart
- Refrigeration recommended (can be at room temperature up to 28 days)
- Do not mix with any other drug in the nebulizer
ALL INHALED
Azithromycin is the only antibiotic taken __ to reduce __ and __.
Fill in the blank
- Orally
- Inflammation
- Exacerbations
Why most CF patients need to supplement their diets with pancreatic enzyme products (PEPs)?
- The thick mucus in CF obstructs pancreatic enzyme flow, resulting malabsorption
- PEPs are needed to help break down fat, starches and protein to help digest food, maintain weight and improve nutrient absorption. AKA pancreatic enzyme replacement therapy (PERT)
- PEPs are formulated to dissolve in the more basic pH of the duodenum
- The dose is individualized for each patient and is based on the lipase component
- The dose is adjusted every 3-4 days until stools are normalized (no greasy, oily, foul-smelling)
