Asthma is a chronic inflammatory condition in which the airways swell, causing a narrowing. It is often associated with extra mucous production, bronchospasm, shortness of breath, and wheezing, and affects the daily lives of sufferers. It has been documented that 340 million people around the world have been diagnosed with asthma. Regardless of severity, all asthmatics are at risk of exacerbations, including severe attacks. Best estimations have concluded that around 175 million attacks happen annually.
One of the main problems with asthma, is the overreliance of asthmatic patients using albuterol for symptom relief, which has been confounded by the lack of compliance with maintenance medication use. While the use of short acting beta-2 agonist (SABA), commonly known as albuterol, does have the benefit of bronchodilation, it does nothing to address underlying airway inflammation. These patients are then at greater risk of having asthma attacks. While both US and international guidelines suggest using SABAs along with an inhaled corticosteroid and long acting beta agonist (ICS-LABA) as maintenance medication, international guidelines have changed to include ICS-LABA as a rescue inhaler also.
Several international trials have looked at using ICS-LABA as a rescue inhaler. The results have been very impressive. One such study has been the Novel START trial. This trial was designed to replicate real world scenarios. It was a 52 week trial including 675 adults who were diagnosed with mild intermittent and persistent asthma. The participants were randomized to one of three groups, the albuterol group (only used PRN albuterol), the budesonide maintenance group (budesonide twice daily with albuterol PRN), and budesonide-formoterol group (budesonide-formoterol PRN). What was very impressive was the 51% decrease in asthma exacerbations with the budesonide-formoterol group to the albuterol group. Comparing the budesonide-formoterol group to the budesonide twice daily with albuterol PRN saw no difference.
The SYGMA 1 and SYGMA 2 trials saw similar results. These trials demonstrated that budesonide-formoterol PRN was as effective in preventing exacerbations as maintenance budesonide. The SYGMA and START trials, along with similar results in the SIENNA trial have led Dr Gary Wong and others, to the conclusion that using budesonide-formoterol as a rescue inhaler is an acceptable alternative to budesonide as a maintenance treatment in mild asthma. This followed with the conclusion that using a PRN budesonide-formoterol treatments could reduce the risk of exacerbations by 50% compared to PRN SABA treatments.
The SMART strategy trial yielded similar results. 22,500 patients were enrolled in this trial, including children. The budesonide-formoterol as maintenance and rescue group saw 32% fewer exacerbations than the budesonide-formoterol as maintenance (at the same dosing) with albuterol rescue group. They also saw fewer emergency room visits and hospitalizations. What is interesting is that even when the dosing of the budesonide-formoterol was increased in the group with albuterol as the rescue inhaler, there was still a 23% fewer exacerbations in the group with budesonide-formoterol as a rescue.
There were two other important points in the SMART trial. When compared to just using budesonide as maintenance with albuterol as a rescue, the budesonide-formoterol as maintenance and rescue was superior. The other more significant point was the effect in children between the ages of 4 and 11. These asthmatics saw a reduction of 50% using budesonide-formoterol as maintenance and also as a rescue compared to just maintenance with albuterol as rescue, which could lead to a drastic reduction in pediatric asthma exacerbations.
As the guidelines for asthma are updated, the use of Symbicort as a rescue inhaler should increase. Some institutions have already adopted this off-label use in the US, as the overwhelming evidence points to the superiority of it compared to albuterol.
The one consideration is how the medication is delivered. In the US budesonide-formoterol is commonly known as Symbicort and comes in an aerosolized metered dose inhaler. In the above listed studies Symbicort Turbuhaler was used. Symbicort Turbuhaler is a dry powder inhaler.
- Symbicort Turbuhaler has been shown to be superior as a rescue inhaler than albuterol in asthmatics
- Albuterol PRN as the sole use of treating asthma increases the risk of having severe asthma exacerbations
- The use of Symbicort Turbuhaler in children has been shown to be effective in treating asthma exacerbations
- Boyles, S. (2019, May 22). As-Needed Symbicort Beats Rescue Albuterol for Mild Asthma. MedPage Today. https://www.medpagetoday.com/meetingcoverage/ats/80003
- Asthma patients should use ICS-LABA for rescue as well as maintenance, SMART says. (2018, August 12). PulmCCM. https://pulmccm.org/asthma-review/ics-laba-for-rescue-maintenance-asthma/
- New data show Symbicort reduces attacks in mild asthma when used as an anti-inflammatory reliever. (2019, May 20). Www.Astrazeneca.Com. https://www.astrazeneca.com/media-centre/press-releases/2019/new-data-show-symbicort-reduces-attacks-in-mild-asthma-when-used-as-an-anti-inflammatory-reliever-20052019.html#