In 2007, The Sopranos was a hit TV show, patterned jeggings were a fashion trend, and the National Asthma Education and Prevention Program (NAEPP) sponsored by the National Institutes of Health released the second edition of the Asthma Management Guidelines.
Much has changed since 2007, including in the area of asthma. The NAEPP recently released the third edition of the asthma management guidelines to cope with these changes. This update reflects recent advances in our understanding of the disease mechanisms that cause asthma and current best practices for managing asthma symptoms. As such, the updated guidelines are an important tool, improving the ability of physicians and patients to control asthma and minimize the impact of this disease on their lives.
The toll of asthma in the United States
Asthma is a chronic lung disease that affects approximately 5% to 10% of the American population. It is characterized by symptomatic periods of wheezing, chest tightness and shortness of breath alternating with periods of essentially normal breathing. Symptomatic episodes can be extremely debilitating or even fatal – each year about 3,500 people die from asthma, many of them children. Like many diseases, the effects of asthma are greater in minority and economically disadvantaged patients. There is no cure for asthma, so therapy focuses on preventing and treating symptom flare-ups, called exacerbations.
New asthma guidelines update treatment recommendations
The main focus of the updated guidelines is the treatment of asthma. Most asthma treatments treat two causes of asthma symptoms: inflammation of the airways and constriction of the airways. Inflammation of the airways in asthma is caused by an overabundant and / or inappropriate immune response. It is usually treated with steroids, which help control inflammation or swelling in the airways over time.
Airway constriction is controlled by the nerves in the airways. There are two main types of nerves in the respiratory tract, sympathetic and cholinergic. The sympathetic nervous network, in particular the beta-2 nerve receptors, is the most common neural target in the treatment of asthma. Drugs that activate beta-2 nerve receptors are called beta agonists and. they are usually given as inhaled medication. Beta-agonists are bronchodilators; they relax the muscles of the airways, allowing the constricted airways to reopen. There are two basic types of beta agonists used in asthma: short-acting, rapid-onset drugs (SABA), which are used for immediate symptom relief; and longer-acting and (usually) long-acting (LABA) drugs, which are used for maintenance therapy.
Previously, asthma patients requiring daily maintenance or control therapy used separate steroid and beta-agonist inhalers to manage inflammation and airway constriction. LABAs are preferred for maintenance therapy because of their longer duration of action. But for patients already using a steroid and LABA for maintenance therapy, using an SABA for rupture symptoms meant having a second (if maintenance therapy used a steroid / LABA inhaler combination) or a third (if separate steroid inhalers and LABA are used maintenance) rescue inhaler. This approach is burdensome and disruptive for patients.
The update provides guidance on using a new type of inhaler that combines a steroid with a LABA as both a controller and a rescue medication. The use of a single inhaler for maintenance and lifesaving therapy is a more efficient approach than one who uses multiple inhalers. First, it is easier to use one inhaler correctly than it is to take multiple doses of multiple inhalers. Second, using a combination inhaler for rescue treatment both provides immediate symptom relief and increases the steroid dose. Thus, this approach increases the amount of anti-constriction and anti-inflammatory drugs.
However, not all combination inhalers are suitable for this approach. To be used for both maintenance and rescue, LABA must have a rapid effect. One LABA, formoterol, has a rapid onset of action, and the guidelines describe which combination therapy is effective as both a control and rescue therapy, and how to integrate it into the treatment of asthma.
Recent evidence has shown that cholinergic nerves also play an important role in regulating the size of the airways in asthma. The updated guidelines incorporate these findings to include recommendations on the use of long-acting anti-cholinergic therapies (LAMAs), such as tiotropium (Spiriva HandiHaler) or umeclidinium (Incruse Ellipta), to treat asthma.
A new therapeutic approach targets specific inflammatory cells
most recent studies in asthma focused on identifying subgroups of asthma patients based on distinct inflammation patterns. These studies have led to the development of new therapies specifically targeting particular types of inflammatory cells and their products. These therapies are very specific and do not work for all asthmatics. And they can sometimes cause serious, even fatal, allergic reactions. The updated guidelines provide general advice on when this new approach can be incorporated into a patient’s asthma management strategy. However, as this area is still new, this edition of the guidelines does not provide specific recommendations for these drugs.
The new guidelines also cover the safe use of leukotriene inhibitors, zileuton (Zyflo) and montelukast (Singulair). These are effective therapies for asthma, but sometimes they can cause serious side effects. In particular, montelukast has been associated with depression. The FDA recently added a warning regarding this concern to this drug. The guidelines describe how it can be used safely.
Nitric oxide measurements can be used for the diagnosis of asthma
The update also provides advice on using new techniques to diagnose asthma. The activity of cells causing inflammation in the airways of people with asthma results in a by-product, called nitric oxide, which is exhaled when the person breathes. Reliable measurements of exhaled nitric oxide have become widely available, and new asthma guidelines explain how to incorporate these measurements into the diagnosis of asthma.