Respiratory Medications, Understanding Options, and Indications

December 27, 2022 - Over the past couple of years, healthcare industry members have had to become fast experts on treating respiratory diseases. With the progression of the COVID-19 pandemic and the lingering pulmonary effects associated with infection, understanding how to treat respiratory diseases properly and the indication for respiratory medications is critical.

Overview of Respiratory Disease

Respiratory diseases can be acute or chronic. For many classifications of respiratory illness, there are acute and chronic versions. Treating the condition can depend on whether it is acute or chronic. According to the CDC, respiratory diseases may include allergies, asthma, influenza, pneumonia, tuberculosis, bronchitis, chronic obstructive pulmonary disease (COPD), silicosis, and mesothelioma. The University of Texas Southwestern Medical Center also notes that respiratory disorders may include cystic fibrosis and emphysema.

Additionally, many acute respiratory illnesses may become chronic if they cause lung damage or go untreated. For example, the American Lung Association notes that COVID-19 can lead to post-covid conditions — otherwise known as long covid — including lingering pulmonary issues such as difficulty breathing, shortness of breath, and cough.

Chronic Respiratory Illness

The WHO states that chronic respiratory diseases can be associated with symptoms such as frequent shortness of breath, sputum production, and chronic cough.

Globally, approximately 262 million people struggle with asthma. According to the CDC, as of 2021, about 8% of adults in the United States had asthma. Additional asthma incidence includes a 6.5% prevalence rate in children under 18.

In a 2018 National Ambulatory Care survey, asthma accounted for approximately 5.8 million office visits each year and 1.6 million emergency department visits. Annually, asthma contributes to roughly 4,145 deaths in the US alone.

On top of that, nearly 3 million people die of COPD each year, accounting for 6% of all deaths globally.  Of those 3 million COPD deaths, 90% occur in low- and middle-income countries. In the US, COPD is the sixth leading cause of death.

Treating pulmonary disease begins by diagnosing the type of illness, as different conditions have varying pharmacotherapeutic interventions.

Pharmacotherapeutic Interventions for Respiratory Disease

In an article published in Respiratory Therapist (RT) Magazine, Bill Pruitt, MBA, RRT, CPFT, AE-C, notes that most pharmacological interventions for respiratory disorders are inhaled. Despite that, some medications may be administered through enteral, parenteral, transdermal, or topical routes.

Inhaled medications allow providers to reduce the dose required for therapeutic effects, minimize adverse effects, and treat the patient quickly. As a bonus, these treatment methods are typically pain-free, safe, and convenient, allowing for easier treatment.

Bronchodilators

The first category of pharmacotherapeutic interventions for respiratory illness is bronchodilators — medications that are often delivered through inhaled medication. There are two subcategories of bronchodilators: sympathomimetic (adrenergic) and parasympatholytic (anticholinergic).

Under each of those two subcategories are short and long-acting versions of these medications. Short-acting medications typically have an effective duration of 4–6 hours, while long-acting drugs can be effective for up to 12 hours. 

Adrenergic bronchodilators stimulate or mimic the sympathetic nervous system, while anticholinergic bronchodilators suppress the parasympathetic nervous system.

Albuterol, one of the most prescribed bronchodilators, is a short-acting adrenergic bronchodilator that acts as a receptor agonist on ß₂ receptors.

Other adrenergic bronchodilators include salmeterol — a long-acting ß₂ adrenergic agonist (LABA), levalbuterol, and formoterol.

According to RT Magazine, short-acting ß₂ adrenergic agonists (SABAs) are used to treat bronchospasms and shortness of breath experienced by many patients with asthma and COPD. LABA medications also treat patients with asthma and COPD but provide longer-term relief.

In the publication in RT Magazine, Pruitt notes, “Anticholinergic medications provide relief from bronchospasm and shortness of breath. They can be used alone or in combination with SABA and LABA. They are frequently prescribed for patients with asthma or COPD.”

The most common anticholinergic bronchodilator is ipratropium, which acts on muscarinic receptors to suppress the parasympathetic nervous system and block the transmission of a response.

Corticosteroids

Corticosteroids are another standard treatment for patients with respiratory diseases. Most often, corticosteroids are used for treating asthma; however, some patients with COPD may also be prescribed these medications.

According to RT Magazine, “Corticosteroids inhibit many of the cells involved in the inflammatory response (such as eosinophils, T-lymphocytes, mast cells, and dendritic cells) and help to increase the diameter of the airways by reducing swelling.”

Although corticosteroids are beneficial in multiple healthcare sectors, they are often associated with adverse effects, including hypothalamic, pituitary, and adrenal gland suppression, mood changes, osteoporosis, hypertension, and more. However, prescribing this class of medications as an inhaled therapy for respiratory diseases can minimize the risk of adverse side effects.

Inhaled corticosteroids have a set of adverse effects, which can include candidiasis, vocal changes, and cough. For some patients, using a spacer and metered dose inhaler (MDI), brushing teeth, and gargling water can reduce these effects by getting rid of residual medication.

Common corticosteroids include fluticasone, budesonide, and mometasone. Recently developed medications and technologies have allowed a reduction in the number of puffs required for a patient to experience effective symptom relief. Many newer drugs require only one puff, while older medications require between four and ten puffs. These advancements have also helped reduce the risk of side effects.

Mast Cell Stabilizers and Auto-IgE Antibodies

Another class of pharmacotherapeutic medications for respiratory disorders is mast cell stabilizers and anti-IgE antibodies. Mast cell stabilizers prevent the release of histamine, leukotrienes, and cytokines from mast cells. These components are considered asthma-related chemical mediators. Currently, available mast cell stabilizers include nedocromil and cromolyn sodium.

Under anti-IgE antibodies, omalizumab is the only available medication. This type of medication prevents the release of chemical medications — similar to mast cell stabilizers. The critical difference is that this kind of medication prevents the binding of immunoglobulin E (IgE). Omalizumab is injected subcutaneously every 2–4 weeks.

In his article for RT Magazine, Pruitt writes, “According to the GINA guidelines, the use of omalizumab should be considered for patients who have severe, uncontrolled asthma despite the regular use of inhaled steroids. Omalizumab should be considered an add-on medication; the other drugs being used should be continued as indicated by asthma severity.”

This class of medication is exclusively used for asthma treatment rather than other respiratory diseases.

Leukotriene Receptor Antagonists

Leukotrienes are a part of the inflammatory cascade in asthma. Mast Cell Stabilizers and anti-IgE antibodies prevent the release of leukotriene (and other compounds) altogether. However, another class of medications, leukotriene receptor antagonists, works to block their effects. Zafirlukast, montelukast, and zileuton are currently available leukotriene receptor antagonists.

Other Respiratory Medications

Antihistamines and adrenaline are delivered orally and restricted to treating allergic reactions and asthma. They can be found over the counter as pills. In some cases, epinephrine is prescribed and given intramuscularly or subcutaneously.

Respiratory stimulants such as doxapram, progesterone, and caffeine can also treat apnea and COPD in some patients.

Pulmonary surfactants have been used since the 1990s to treat newborns with underdeveloped lungs and pulmonary systems. Surfactant therapy has also been studied for acute lung injury treatment and adult respiratory distress syndrome.

Antimicrobials and antivirals may also treat lung issues arising from viral and bacterial infections.

Looking Ahead

Based on the current trajectory, the rate of acute and chronic respiratory conditions will continue to rise in the coming years. Fueled by climate change — which contributes to air pollution, worsened air quality, and rising temperatures — respiratory illness continues to impact many of the world’s population. With this in mind, providers of all specialties should consider advancing their knowledge of respiratory disease, its impacts, and effective treatment or management strategies.