What are the current treatment options for severe asthma?
- Identifying and avoiding or reducing exposure to triggers or things that cause asthma to worsen.
- Taking medications regularly.
The major groups of currently used asthma medications include:
Anti-inflammatory Drugs. Inhaled corticosteroids (ICS) are the key drugs used for controlling the underlying inflammation in asthma. Oral corticosteroids (OCS) such as prednisone, when used for maintenance, are reserved for patients with severe asthma. These drugs typically serve as maintenance medications.
Bronchodilators. These drugs act principally to dilate the airways by relaxing airway smooth muscle. Bronchodilators reverse and/or inhibit airway constriction and related symptoms of acute asthma, but do not reverse airway inflammation. Bronchodilators come in two basic forms: maintenance medications such as long-acting beta-agonists (LABA), which serve to produce prolonged bronchodilation up to 12 hours; and short-acting rescue medications, which are fast-acting and can alleviate the symptoms of asthma attacks for up to 4-6 hours.
Other medications that may be considered when long-term control is still unattainable include methylxanthines, anticholinergics, leukotriene inhibitors, and IgE inhibitors (omalizumab or Xolair®).
As asthma symptoms increase, the dosage level and number of maintenance medications prescribed may be increased to reach an acceptable level of control. Patients with severe asthma usually have more symptoms and therefore take higher doses as well as more types of medications than do patients with mild or moderate asthma.
Despite the abundance of medications to treat asthma, there are significant limitations and risks associated with the existing standard of care, including:
- Limited Efficacy in Patients with Severe Asthma. A number of recent surveys indicate that symptoms are still poorly controlled in severe asthma patients, and that this patient population often continues to experience frequent and serious symptoms despite taking the highest doses of asthma medications (Partridge 2007). This limited efficacy is still only possible when the patient routinely takes their medicine as prescribed, typically twice a day, every day.
- Poor Patient Compliance. According to a 2007 report issued by the Global Initiative for Asthma (GINA 2007), non-compliance in taking asthma maintenance medications is estimated at approximately 50%. Non-compliance, in particular by severe asthmatics, may be an additional contributing factor to the increased number of emergency room visits and hospitalizations for these patients.
- Side Effects. Existing asthma medications carry with them possible and sometimes serious side effects. As with any medication, side effects typically become a greater concern as dosages increase and duration of treatment is extended indefinitely, which is the case for patients with severe asthma.
- Corticosteroids: Side effects of prednisone and other oral corticosteroids range from mild annoyances to serious, irreversible damage, and they occur more frequently with higher doses and more prolonged treatment. Side effects with chronic administration include immune system, adrenal and growth suppression; osteoporosis; skin thinning; hypertension; cataracts; glaucoma; muscle weakness; and increased risk of infection. Short term side effects include stomach upset, headache, dizziness, trouble sleeping, fluid retention, weight gain, high blood pressure, loss of potassium, elevation of cholesterol levels and vision changes.
- Bronchodilators: The possible side effects of short-acting rescue medications include rapid heartbeat, skeletal muscle tremor, potassium deficiency, increased lactic acid, headache and hyperglycemia. Long-acting beta-agonists may paradoxically cause severe exacerbations in some patients, and death when those episodes occur (GINA 2007).
- Other Drugs: The side effects of omalizumab (Xolair®) include anaphylaxis, injection site reactions and viral infections.
- Significant Ongoing Healthcare Burden. Because the existing medical options provide poor control for some severe asthma patients, they are often forced to miss work or school and require unscheduled physician office visits, emergency room visits and hospitalizations.
As a result of limitations of existing medications, there has been a significant unmet medical need to improve the care for patients with severe asthma by better controlling their asthma symptoms. Bronchial thermoplasty delivered by the Alair® System is a new long-lasting treatment option for this well defined population of patients with severe asthma.
Xolair is a registered trademark of Genentech, Inc.
Partridge MR. Examining the unmet need in adults with severe asthma. Eur Respir Rev 2007; 16:104, 67-72.
GINA (Global Initiative for Asthma) 2007. Global Strategy for Asthma Management and Prevention. Workshop report in collaboration with National Institutes of Health (NIH) National Heart, Lung, and Blood Institute NHLB/WHO 2007.
