| Summary : Exercise-induced bronchoconstriction (EIB) is a common condition that affects many people, especially those with asthma. It is characterized by the narrowing of the airways in response to physical activity or exercise, causing symptoms such as coughing, wheezing, shortness of breath, and chest tightness. Pharmacists play a critical role in the management of EIB, including educating patients on the appropriate use of inhaled bronchodilators and corticosteroids, screening for potential adherence problems, and advising on proper medication administration. They can also advise patients on strategies to prevent and manage EIB, including warm-up exercises, avoiding triggers, and monitoring increasing symptoms. By working collaboratively with healthcare teams, |
According to the CDC, 4.9 million patients visit their doctors annually for asthma, and 1.2 million patients diagnosed with asthma visit the emergency department. Exercise-induced bronchoconstriction ( EIB) is a common condition that can affect patients with or without a diagnosis of asthma . Exercise can cause shortness of breath in most people; However, patients with asthma will also experience tightness in the lungs, making it difficult to breathe. Up to 90% of patients diagnosed with asthma also have EIB, showing how widespread it is. To adequately advise patients on drug therapy, pharmacists and physicians must have a thorough understanding of the mechanism and symptoms of EIB.
Prevalence and risk factors
The Asthma and Allergy Foundation of America estimates that about 25 million Americans, or nearly one in 13 people, have asthma. EIB can occur in both asthmatic and non-asthmatic patients; However, it is believed to affect approximately 90% of asthmatics . Children are a common group affected. EIB is present in 40% to 90% of asthmatic children, particularly in those with severe asthma who do not receive adequate medication therapy. Given the prevalence of asthma, it is essential that providers become familiar with the risk factors for EIB.
Additional risk factors for EIB include allergies, allergic rhinitis, and a history of asthma or wheezing. Since EIB is caused by exercise, strenuous exercise and sports are likely to cause bronchospasm and constriction due to increased breathing. The likelihood of experiencing BIE is also influenced by environmental variables. Factors such as humidity, cold air, and pollutants are linked to an increased risk of EIB. Breathing in cold environments is often a major contributor to BIE and is common in those who are exposed to cold, dry air.
Mechanism of action
The mechanism of action of EIB must be understood to ensure that the appropriate treatment option is prescribed. The two proposed mechanisms to cause EIB are drying of the airways and cooling of the mucosa . When the fluid on the surface of the airways in the lungs dries up due to excessive breathing caused by exercise, coughing and mucus production increase. This loss of water produces a hyperosmolar environment , displacing water out of the cell and therefore shrinking it. As a result, inflammatory mediators such as histamines, prostaglandins and leukotrienes are released . Additionally, as mucus cools with breathing, cholinergic receptors in the airways are stimulated, leading to increased mucus production and smooth muscle tone. These dual mechanisms feed off each other, causing bronchoconstriction when people exercise.
Recognizing the signs of EIB
The signs and symptoms of EIB are often indistinguishable from the symptoms of asthma. The differentiating factor between the two is when these symptoms occur after 5 to 10 minutes of exercise. Symptoms such as chest tightness, shortness of breath, cough, wheezing and shortness of breath occur in patients with EIB. Additionally, these symptoms typically dissipate within 30 to 90 minutes and result in a refractory period of 1 to 3 hours .
EIB Treatment Options
Although EIB is considered an asthmatic condition, the treatment process is somewhat different for patients with EIB alone than for patients with concomitant asthma and EIB . Patients with EIB alone are usually recommended an inhaled short-acting beta 2 agonist (SABA) to use 5 to 20 minutes before beginning exercise. However, if these patients end up requiring a daily SABA, adding a controller medication such as an inhaled corticosteroid (ICS) would be more effective.
For patients with EIB and diagnosed asthma, the addition of a control agent, such as an inhaled corticosteroid (ICS) used daily, is strongly recommended. Use of low-dose inhaled budesonide and formoterol before exercise, as opposed to SABA monotherapy before exercise, was superior in reducing EIB symptoms, according to a 6-week study of the use of ICS with formoterol in people with moderate asthma. Furthermore, it found that the use of ICS-formoterol is non-inferior in reducing EIB compared to daily use of ICS and SABA as needed. These treatment options serve as a baseline and may need to be adjusted for resolution of symptoms. Additionally, it is recommended that patients with seasonal allergies take an oral antihistamine daily before exercise.
Dangers of overuse of inhaled short-acting beta 2 agonist (SABA)
Although SABAs are the first-line therapy for the management of EIB, providers should be aware of the long-term risks associated with SABA use. In fact, many patients receiving SABA tend to abuse them when their asthma is not controlled. Excessive use of SABA is risky as it increases the chance of exacerbations and asthma-related mortality. According to a 2004 retrospective study of 100,000 asthma patients, people who needed to use three or more SABA inhaler cartridges per year were more likely to experience an asthma exacerbation. Additionally, excessive use of beta 2 agonists can lead to tolerance , which can greatly reduce their effectiveness in treating and preventing EIB. This is a major issue of concern, particularly if patients begin refilling their inhalers too soon or more frequently, in which case pharmacists can intervene quickly if any trends of non-compliance or misuse are detected.
Role of the pharmacist
Historically, pharmacists are considered the most accessible healthcare provider. A recent study found that patients visit their community pharmacies approximately 1.5 to 2 times more frequently than their physicians or other qualified health professionals. This means that community pharmacists will see patients more than doctors, giving them the opportunity to make valuable interventions. Asthma medications prescribed to patients may lose their effectiveness over time. This could be attributed to several factors such as asthma severity, exercise intensity, SABA tolerance, or patient non-adherence. Patients with EIB experience symptoms similar to those with asthma, so it is important to counsel both new and existing patients when receiving their medication from the pharmacy.
During counseling, pharmacists can demonstrate to newly diagnosed patients with EIB how and when to use their inhaler. There are many inhalers on the market, and each has its own unique use requirements, such as the number of times the inhaler must be primed before use and after use dates.
Patients with EIB alone are typically prescribed only one reliever medication; Asthma patients will also have a controller medication. The use of multiple inhalers can become confusing for patients, making comprehensive patient counseling even more essential. Pharmacists should also check for possible drug interactions and contraindications and alert patients to possible adverse effects. Additionally, pharmacists must follow patients when they receive their new medications and refills, ensuring that their EIB, with or without a diagnosis of asthma, is being treated appropriately.
Although EIB is typically managed with prescription medications, pharmacists also have the responsibility of advising patients on various non-pharmacological methods to prevent EIB. Patients should not rely solely on medication to relieve and prevent EIB, but should also make lifestyle modifications. The most studied and validated method to prevent EIB is to induce a refractory period by performing a moderate physical warm-up before exercise. This essentially “prepares” the lungs for exercise by reducing bronchoconstriction over the next 2 hours. Additionally, dietary supplements such as omega-3 fatty acids (fish oil) and vitamin C may be beneficial. In general, maintaining a healthy body weight and a consistent exercise routine can help improve EIB.
Conclusion
Exercise-induced bronchoconstriction ( EIB) is a common condition experienced by patients with and without asthma. It is a physiological phenomenon that can quickly get out of control and impose limitations on patients who wish to live a healthy lifestyle through exercise. The health of people with BIE may deteriorate as a result of excessive prescription and use of SABA. Therefore, it is important for pharmacists to be aware of their patient population and educate patients not only about the use of their prescribed medications, but also how to implement non-pharmacological interventions that can further improve their quality of life.
