Asthma Treatments: Bronchodilator Therapies and Controller Therapies

Treatment for many people with asthma is a combination of drugs to prevent symptoms and for quick relief and control (long-acting control drugs) and to provide immediate relief of symptoms that occur ( short relief drugs). The cornerstone of asthma treatment is the initial control of inflammation with long-acting drugs. For some people, Allergic desensitization (when the allergic reaction is the obvious cause of asthma) provides more control. Other important steps in long-term asthma management include monitoring for asthma symptoms (such as monitoring peak flow) and developing an asthma control action plan

Asthma Treatment

When acute exacerbation of symptoms (an asthma attack) occurs, treatment is more likely to be successful when it starts before or immediately after symptoms are recognized. Once an asthma attack begins, even rescue medications can take time to get the situation under control

The typical fast-release drug is a beta-agonist inhaler, such as albuterol. Ideally, a patient's asthma is sufficiently controlled that on-demand treatment is rare. If albuterol is needed more than a couple of times a week, drug treatment should be taken. For most patients, this means a steroid inhaler, although some patients respond well to leukotriene modifiers as first-line therapy. If symptoms are still not well controlled, higher dose steroid inhalers or the addition of a long-acting beta agonist may be considered. If further intensification of therapy is required, other causes of wheezing and should be looked for and the patient should be referred to a pulmonologist

 

Treatment regimens vary according to the stage (classification) and nature of the symptoms. Major asthma medications can be divided into bronchodilators, which quickly relieve symptoms by mainly relaxing the smooth muscle in the airways, and controllers, which inhibit the underlying inflammatory process

Quick-relief asthma treatments

Bronchodilator Therapies or Rescue inhalers

• Short-acting beta agonists. These inhaled which are bronchodilators, quick rescue within minutes to rapidly ease symptoms during an asthma attack

Beta-2 agonists: Β2 agonists activate β2 adrenergic receptors, which are widely precise in the airways. The β2 receptors are coupled via a G protein stimulating adenyl cyclase, resulting in an increase in intracellular cyclic adenosine monophosphate (AMP), which relaxes smooth muscle cells and inhibits some inflammatory cells, particularly mast cells

Short-acting beta agonists can be taken using an inhaler or a portable nebulizer, a machine that turns asthma medications into a fine mist. They are inhaled through a mask or mouthpiece

• Oral corticosteroids, these medications are used to treat severe asthma symptoms, which relieve airway inflammation. When they used for long term can cause serious side effects

• Anticholinergic agents, Muscarinic receptor antagonists prevent cholinergic nerve-induced bronchoconstriction and mucus secretion. They are less effective than β2 agonists in the treatment of asthma, which  prevent all bronchoconstrictor mechanisms, while anticholinergic agents inhibit only the cholinergic reflex component of bronchoconstriction

• Combination quick-relief medicines, an anticholinergic agents and a short-acting beta-agonist

Long-term asthma control medications

Controller Therapies 

Controllers therapies are medications that are used continuously for long-term management to achieve good control of asthma 

• Inhaled corticosteroids medications, which are anti-inflammatory and serve as long-term controller medications

Inhaled Corticosteroids: ICS are the most effective anti-inflammatory agents used in asthma therapy, reducing the number of inflammatory cells and their activation in the airways. ICS reduces eosinophils and airway sputum and the number of activated T lymphocytes and surface mast cells in the airway mucosa. These effects may explain the reduction in AHR observed with chronic ICS therapy

• long-acting β2 agonists (LABA), long-acting β2 agonists, provide long-lasting bronchodilation (12 hours or more) when administered as an aerosol. Long-acting agents are fat-soluble and readily distributed in the outer phospholipid layer of the cell membrane, unlike the more water-soluble, short-acting β2 agonists. Salmeterol is more selective for β22 than albuterol and other broncho-selective by virtue of its property of remaining in the cell membrane of the lung tissue, which determines its longer duration

• leukotriene receptor antagonists (LTRA), which are IMMUNE RESPONSE mediators that provide long-term control

Antileukotrienes Cysteinyl leukotrienes are potent bronchoconstrictors, cause microvascular loss and increase eosinophilic inflammation by activating cys-LT1 receptors. These inflammatory mediators are mainly produced by mast cells and, to a lesser extent, by eosinophils in asthma. Anti leukotrienes, such as montelukast and zafirlukast, block Cys-LT1-receptors and supply modest clinical benefit in Asthma. They are less effective than ICS in controlling asthma and have less effect on airway inflammation, but are useful as adjunct therapy in some no tcontrolled patients with low-dose ICS, although less effective than a LABA

• Theophylline, Theophylline produce bronchodilation by inhibiting phosphodiesterases, which can also cause anti-inflammatory and non-bronchodilator activity through a decrease in the release of mast cell mediators, a decrease in the release of basic eosinophilic proteins, a decrease in the proliferation of T cells, a decrease in release of T cell cytokines and decrease in plasma exudation 

• Anti-IgE antibody, Omalizumab is a blocking antibody that neutralizes circulating IgE without binding to cell bound IgE and thereby inhibits IgE mediated reactions. This treatment has been shown to reduce the number of exacerbations in patients with severe asthma and can improve asthma control

• Anti-IL-5 antibody, Antibodies that block IL-5 (mepolizumab, reslizumab) or its receptor (benralizumab) significantly reduce eosinophils in blood and tissues and reduce exacerbations in patients who have a persistent increase in sputum eosinophils despite maximal ICS therapy

• Combination inhaled medicines, an inhaled corticosteroid along with a long-acting beta-agonist

• Leukotriene Modifiers, oral leukotriene receptor antagonists that reduce the proinflammatory (increased microvascular permeability and airway edema) and bronchoconstriction effects of leukotriene D4. They are not used to treat acute exacerbations and should be taken regularly, even during symptom-free periods

In addition to pharmacological interventions, patients should be advised to avoid triggers by minimizing exposure to allergens and maintaining a clean living environment. If an asthma patient currently smokes, quitting smoking is essential. Doctors should also create an "action plan" for the patient based on peak threshold flow measurements to increase therapy and seek medical attention