Introduction of Asthma, Which is Treated by Bronchodilator

Abstract

Numerous comorbidities, including cardiovascular disorders, depression, diabetes mellitus, dyslipidemia, osteoporosis, rhinosinusitis, and primarily gastro-oesophageal reflux disease and allergic rhinitis, are frequently linked to asthma. Despite the fact that bronchodilators are crucial for treating asthma, their overall effects on comorbid asthma, whether positive or negative, are not well described. This narrative review investigates how bronchodilators may affect asthmatic comorbidities.

Keywords

Introduction

HOW BRONCHODILATOR ACT ON ASTHMA

Types of Bronchodilators & Their Action

Type	Example Drugs	Mechanism of Action
β?-adrenergic agonists	Salbutamol (Albuterol), Formoterol, Salmeterol	Stimulate β?-receptors → relax bronchial smooth muscle by increasing cAMP
Anticholinergics	Ipratropium bromide, Tiotropium	Block acetylcholine (ACh) on muscarinic receptors → prevent bronchoconstriction
Methylxanthines	Theophylline, Aminophylline	Inhibit phosphodiesterase enzyme → increase cAMP → relax airway muscles

Bronchodilators Used in Asthma

Class/ Type	Examples	Mechanism of Action (MOA)	Advantages	Disadvantages/ Side Effects
1. β?-Adrenergic Agonists	Short-acting: Salbutamol (Albuterol), Terbutaline Long-acting: Salmeterol, Formoterol	Stimulate β?-receptors in bronchial smooth muscle → ↑ cAMP → muscle relaxation → bronchodilation	Rapid relief of acute attack (SABA) Long-term control (LABA) when combined with corticosteroids	Tremors, nervousness, tachycardia, tolerance on overuse
2. Anticholinergics (Muscarinic Antagonists)	Ipratropium bromide, Tiotropium	Block muscarinic (M?) receptors → inhibit acetylcholine → prevent bronchoconstriction	Useful in patient’s intolerant to β?-agonists Effective in COPD-asthma overlap	Dry mouth, throat irritation, headache
3. Methylxanthines	Theophylline, Aminophylline	Inhibit phosphodiesterase (PDE) → ↑ cAMP → bronchodilation; also, mild anti-inflammatory effect	Oral route available Improves diaphragm contractility	Narrow therapeutic index, nausea, arrhythmia, insomnia
4. Combination Inhalers	Salmeterol + Fluticasone Formoterol + Budesonide	Combine bronchodilation (β?-agonist) and anti-inflammatory (steroid) actions	Dual benefit: long-term control + symptom relief	Costly, potential steroid-related side effects (oral thrush)

ADVANTAGES

• Provide quick relief from asthma symptoms
• Relax bronchial smooth muscles and open airways
• Improve airflow and oxygen supply to the lungs
• Reduce wheezing, coughing, and shortness of breath
• Useful in both acute attacks and long-term control (depending on type)
• Enhance effectiveness of inhaled corticosteroids when used in combination
• Improve exercise tolerance and daily activity
• Can be administered easily through inhalers or nebulizers
• Reduce frequency and severity of asthma attacks
• Improve overall quality of life for asthma patients

DISADVANTAGES

• may result in muscle shaking or tremors.
• may result in tachycardia, or elevated heart rate, or palpitations.
• Anxiety, restlessness, or nervousness may arise.
• You might feel lightheaded or have a headache.
• Irritation of the throat and dry mouth, particularly when taking anticholinergics.
• Theophylline, also known as methylxanthine, has a limited therapeutic range and a potential for toxicity.
• Sleeplessness, nausea, and vomiting are examples of potential adverse effects.
• Ineffective at reducing airway inflammation; corticosteroids are required for that.

REFERENCE

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