Introduction:
Bronchial asthma is a chronic inflammatory disease characterized by hyperresponsiveness of the tracheobronchial smooth muscle to various stimuli causing narrowing of the airways and increased secretion, mucosal edema, and mucus plugging. This makes it difficult for the air to flow easily through the airways and to breathe.
What Are the Clinical Features of Asthma?
Asthma can present as:
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Cough typically occurs at night or early morning.
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Wheezing.
What Are the Triggering Agents in Asthma?
The triggering agents include:
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Allergens such as seafood, pollen, and mold.
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Air pollution and toxins.
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Infections such as cold, flu, or pneumonia.
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House dust mites.
What Are the Different Types of Medications Available to Treat Bronchial Asthma?
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Quick-relief medicines.
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Controller medicines.
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Combination therapy.
What Are Quick Relief Medicines in Bronchial Asthma?
The drugs relax the muscles around the airways. These drugs are most effective against acute asthma attacks.
They can be of three types:
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Beta 2- Agonists: The adrenergic drugs cause bronchodilation through beta two receptor stimulation. The beta-two adrenergic receptors are primarily found on the alveolar cells and have less or no effects on other organs. These drugs are the drug of choice in reversible airway obstruction but should be used cautiously in hypertensive and cardiac patients.
It can be further classified into the following:
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Short-Acting Beta Agonists(SABA) is the best drug for relieving asthma attacks. They are also used to prevent exercise-induced asthma. Most drugs, especially the inhaled ones, act within minutes. Examples- Salbutamol and Terbutaline.
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Long-Acting Beta Agonists(LABA): They are used to prevent asthma attacks and are effective for 12 hours, so it is administered twice daily. For example- Salmeterol and Formoterol.
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Ultra Long-Acting Beta-Agonists: They are effective for up to 24 hours, so only a single dose per day is given, for example- Indacaterol.
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Anticholinergics: These are another group of bronchodilators that can provide quick relief from an asthma attack. They are long-acting muscarinic antagonists which cause bronchodilation and decrease mucus production like Ipratropium bromide and Tiotropium. The common adverse effects include nasal dryness, nasal irritation, dry mouth, nasal bleeding, and trouble breathing.
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Methylxanthines are also bronchodilators; the most common example is Theophylline. It is a narrow therapeutic index drug that requires therapeutic drug monitoring. So, it is rarely used. The adverse effects of the drugs include headache, nausea, and vomiting.
What Are Controller Medicines In Bronchial Asthma?
The drugs are named controllers since they control or prevent the symptoms. Corticosteroid drugs are the most potent anti-inflammatory drugs and have been an important part of asthma treatment for years. They help in reducing swelling and mucus production. These drugs are most effective against prophylaxis in chronic asthma.
Different routes to administer the drugs. They include
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Inhalational Corticosteroids: The inhaled versions are best because they act on the lungs directly and have no or zero systemic effects. They can produce oral thrush, so a thorough mouth rinse should be done after use. Examples of inhaled corticosteroids are- Beclomethasone, Triamcinolone, and Budesonide.
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Oral Corticosteroid: The oral forms may be used in high doses to relieve a severe asthma attack and are generally given for 1-2 weeks, for example- Prednisolone. They have serious long-term adverse effects such as weight gain, osteoporosis, retarded growth, cushingoid features, suppressing ACTH (adrenocorticotropic hormone), cataracts, glaucoma, mood swings, and high blood pressure.
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Intravenous Corticosteroids: Such as hydrocortisone, specifically used in the case of status asthmaticus.
The other drugs used as a controller are:
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Anti IgE Monoclonal Antibody: Omalizumab is an antibody directed against a group of other antibodies known as IgE (expand).
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Leukotriene Antagonist: Like Monteleukast, Zafirleukast. These are leukotriene receptor antagonists, which inhibit leukotriene release. It is a major inflammatory mediator causing swelling. They are indicated for the prophylactic therapy of mild to moderate asthma as an alternative to inhaled corticosteroids. They are well-absorbed drugs. Both drugs are safe and produce a few mild side effects like headaches and rashes.
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Mast Cell Stabilizers: Like Sodium cromoglycate which is administered in an aerosol form by a metered dose inhaler. It is a synthetic chromone derivative that inhibits the degranulation of mast cells by triggering stimuli. Mast cells release mediators like histamine, leukotrienes, and other inflammatory cells. It does not act as a bronchodilator, so it is ineffective if given during an asthma attack. It is not orally absorbed.
What Is a Combination Therapy In the Management of Bronchial Asthma?
Combination therapy has proven to be beneficial in the treatment of asthma. The combination therapy consists of long-acting beta two agonists with an inhaled corticosteroid in a single inhaler device that provides complementary and synergistic effects in managing asthma. It decreases the complexity of the treatment and also improves patient compliance. It can serve not only as maintenance therapy but also as a reliever therapy, just like a short-acting beta agonist. The long-acting beta two agonist helps bronchodilation by relaxing the smooth muscle around the airways, and the corticosteroid reduces the swelling inside the airways.
Common combination asthma medications available are:
1. Combination of Fluticasone and Salmeterol
Fluticasone belongs to the class of corticosteroids, whereas Salmeterol belongs to the class of long-acting beta-agonists. This medication should be used regularly to be effective. It should not be used to relieve sudden asthma attacks. A metered dose inhaler administers the drug. The drug is administered twice daily, 12 hours apart.
2. Combination of Mometasone and Formoterol
Mometasone belongs to the class of corticosteroids, whereas Formoterol belongs to the class of long-acting beta-agonists. A metered dose inhaler can deliver the drug combination. The drug can be administered twice a day, about 12 hours apart.
3. Combination of Budesonide and Formoterol
Budesonide belongs to the class of corticosteroids, whereas Formoterol belongs to the class of long-acting beta-agonists. A metered dose inhaler can deliver the drug combination. The drug can be administered twice a day, about 12 hours apart. The side effects include headache, throat irritation, nasopharyngitis, upper respiratory tract infection, nasal congestion, sinusitis, and stomach upset.
Conclusion
The combination therapy has been effective as a maintenance and reliever agent in both young and adult patients. The combination therapy, in addition to the convenience and patient compliance, also helps towards an individualized approach to asthma management.
