Approximately 30,000 people in the United States have cystic fibrosis (CF), a chronic, progressive genetic disease characterized by thick, sticky mucus. In this autosomal recessive condition, a protein called cystic fibrosis transmembrane conductance regulator (CFTR) is abnormal. CFTR functions as a channel across the membranes of cells that make mucus, saliva, sweat, tears, and digestive enzymes. The CFTR defect causes CF signs and symptoms, with mucus in the lungs, sinuses, and GI tract becoming abnormally viscous. In the lungs, this creates the perfect breeding ground for bacteria.
In 1955, few children with CF survived to school age. Today, the predicted survival age extends beyond the mid-30s. In 2010, the Cystic Fibrosis Foundation Patient Data Registry reported 45% of CF patients were older than age 18. Today, the predicted survival age for CF patients is about age 38.
Longer survival means more nurses are caring for CF patients. This article updates nurses on the latest inhaled therapies, which are crucial to the well-being of CF patients.
CF patients are susceptible to opportunistic airway infections. Early in life, they may become colonized with Staphylococcus aureus or Hemophilus influenzae. With age, Pseudomonas aeruginosa infections become prevalent, affecting 80% of patients by age 25.
Aerosolized medications and airway clearance have long been standard therapy for CF. Various inhaled therapies have helped lengthen survival. Most patients use a bronchodilator by inhaler or nebulizer to open the airways, followed by an inhaled mucolytic, such as hypertonic saline solution (HSS), dornase alfa for inhalation solution (Pulmozyme®), or both, to break up mucus and ease airway clearance.
Patients also may use inhaled antibiotics, which deliver medication directly to the airway. Agents used include tobramycin for inhalation (TOBI®) and aztreonam for inhalation solution (Cayston®). Some patients with signs and symptoms of reactive airway disease may take inhaled corticosteroids as well.
Defective ion chloride transport in CF depletes airway surface liquid volume, impeding mucus clearance. Some CF patients use HSS by nebulizer twice daily to restore the liquid volume. Based on two randomized, controlled trials, some experts recommend 7% HSS to improve lung function and decrease exacerbations in patients age 6 or older. Recent clinical trials showed no benefits of HHS use in infants and young children, so it’s not routinely ordered for these groups.
Pulmozyme is a purified solution of recombinant human deoxyribonuclease I (rhDNase), an enzyme that selectively cleaves DNA. It’s taken by nebulizer daily to break up viscous mucus, making it easier for patients to expectorate and clear the airway. Strongly recommended for chronic maintenance therapy in patients at least age 6 with moderate to severe lung disease, it improves lung function and decreases pulmonary exacerbations. For patients at least age 6 with mild lung disease, it’s recommended for once-daily use as chronic standard therapy.
Inhaled antibiotics, such as TOBI, deliver high concentrations of medication directly to the infected lung with minimal systemic effects. TOBI is strongly recommended for patients at least age 6 who have both a pseudomonas infection and moderate to severe lung disease. This drug, which helps control bacterial load in the lung, is taken by nebulizer twice daily for a 28-day on/off cycle. Clinical trials continue to evaluate the delivery and effectiveness of other antibiotics, such as amikacin, levaquin, and ciprofloxacin. Insufficient evidence exists to recommend other inhaled antibiotics, although in some situations aztreonam, colistimethate, and cephalosporins have been used.
What the future may hold
Although the therapies discussed above have lengthened survival in CF patients, they’re costly and time-consuming to use. CF patients spend more than 2 hours per day inhaling life-sustaining medications and performing airway clearance techniques. This can be a burden for those getting ready for school or work every morning, especially as they must perform the same regimen in the evening. (See the box below.) For some patients, this burden decreases treatment adherence.
Standard inhaled therapies
Cayston, approved by the Food and Drug Administration (FDA) in 2010, is delivered only with the Altera® Nebulizer System with PARI eFlow® technology. This new-generation wet-aerosol delivery system is more efficient and less time-consuming to use than previous systems. A standard nebulizer compressor forces compressed air through a handheld nebulizer cup; liquid in the cup is aerosolized and inhaled. Other administration systems take 20 minutes twice daily to deliver 5 ml of TOBI; eFlow technology reduces inhalation times significantly, delivering medication at a rate of 1 mL/minute. Cayston takes only 2 to 3 minutes to administer, but this nebulizer isn’t safe to use with all drugs. Clinical trials are underway to evaluate the use and safety of this system with other medications.
Researchers also are investigating dry-powder inhalers for delivery of various inhaled medications; these agents may reduce delivery times markedly. In September 2012, tobramycin inhalation powder (TIP) received approval from the FDA’s Anti-Infective Drugs Advisory Committee; full FDA approval for CF use is expected in 2013. Administering TIP reduces treatment time 70% compared to TOBI given by a nebulizer compressor.
The Cystic Fibrosis Foundation, committed to finding new therapies for CF patients, has built a pipeline for development of new treatments, including inhaled therapies that restore salt transport, have anti-inflammatory effects, or fight infection. Some of these agents are delivered in wet or dry formulations using advanced delivery systems.
Faster, more efficient delivery of inhaled medications represents an important treatment advance for CF, improving patients’ quality of life and medication adherence. In the future, these therapies also may be considered for patients with chronic obstructive pulmonary disease, bronchiectasis, primary ciliary dyskinesia, or pseudomonas colonization.
As patient advocates and educators, nurses must be knowledgeable about these treatment advances. They also must be able to assess patients’ knowledge of proper medication use and timing and correct techniques for cleaning the delivery devices—important steps in helping them adhere to prescribed treatment. New-generation therapies not only can add days to the life of a CF patient; they can add life to the patient’s days.
Paula Lomas is the nurse coordinator in the Adult Cystic Fibrosis Center at Morristown Medical Center in Morristown, New Jersey.
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