Asthma is a very common disease of the respiratory system found in adults and children, and it is a complex syndrome that is not easily defined. The symptoms found in affected patients revolve around airway obstruction and increased responsiveness of the airways. There are numerous pharmacologic options available to the physician and patient, and the choice of which agent to use depends on the severity of the asthma, as well as the potential side effects of the medication.
Rescue Medication
These are agonists of the B2 receptors and include albuterol, terbutaline and salbutamol. These are used for acute flare-ups of symptoms and are used on demand and at the lowest dose possible. Increased need for these medications indicates a lack of control over symptoms and indicates a need for additional pharmacologic intervention
Inhaled Corticosteroids (ICS)
These are the most effective way to manage asthmatic symptoms on a long-term maintenance program. They are to be used regularly, and their many benefits include reduction of incidence of asthma exacerbations, improving the quality of lung function and reducing the airway responsiveness that is the culprit for many of the respiratory symptoms. They include beclomethasone, budesonide, fluticasone and triamcinolone. The physician must monitor therapy and keep the patient on the lowest dose possible to minimize the adverse side effects, such as candida occurrence in the mouth and pharynx. With higher doses, systemic absorption is possible with increased adverse effects, in which case it is advised to add a second agent rather than increase ICS dosing.
Long-Acting B2 Agonists (LABA)
When asthma is not controlled by ICS, inhaled LABAs are usually the drugs of choice to add to therapy, but they have not been shown to help those who have not used steroids as of yet. The duration of effects is roughly 12 hours, and administration is twice daily to give round-the-clock coverage. It is noteworthy that monotherapy with just LABAs is not recommended and is even associated with worse outcomes; thus LABAs should always be given concomitantly with ICS. They include symbicort, advair and formoterol (which happens to also have rescue properties due to its rapid onset).
Leukotriene Receptor Antagonists
These agents include montelukast and zafirlukast and work by antagonizing leukotriene effects. They are currently listed as the second choice behind ICS for the management of inflammatory asthma. They also tend to have improved therapeutic functions when rhinitis is present and thus are in consideration for adding to ICS therapy in appropriate circumstances. Their efficacy is ranked at not greater than and usually less than LABA usage; and their use is preferred in addition to ICS instead of doubling ICS dosage.
Oral Corticosteroids
These are used for the treatment of severe asthma flare-ups, and, in very severe asthmatics, can be called upon for maintenance therapy despite wide-ranging adverse consequences. The side effect profile includes immunosupression, hyperglycemia, hypertension, adrenal suppression, weakness, and increased risk of osteoporosis. The physician must regularly monitor patients on these medications and explore possibilities of downgrading when symptoms seem to abate.
References
- Middleton's Allergy: Principles and Practice, 7th ed. Adkinson 2008
- Clinical Cornerstone. "Asthma Management and Prevention: Current Perspectives." Stoloff S. Volume 9, Issue 2 (January 2008)
- Otolaryngologic Clinics of North America. "Asthma: Guidelines-Based Control and Management." Krouse J, Krouse H. Otolaryngologic Clinics of North America - Volume 41, Issue 2 (April 2008)
