Bronchodilators classification
Pro Research Analysisby 
Searched over 200M research papers for "bronchodilators classification"
Major Classes of Bronchodilators
Bronchodilators are mainly classified into three major drug classes: beta2-adrenoceptor (β2-AR) agonists, muscarinic receptor antagonists, and xanthines. These classes are the foundation of current treatment for airway disorders such as asthma and chronic obstructive pulmonary disease (COPD) 159.
Beta2-Adrenoceptor Agonists (β2-AR Agonists)
β2-AR agonists work by relaxing airway smooth muscle, leading to bronchodilation. They are further divided into:
- Short-acting β2-agonists (SABAs), used for quick relief of symptoms.
- Long-acting β2-agonists (LABAs), used for maintenance therapy. Some ultra-long-acting LABAs, such as indacaterol, olodaterol, and vilanterol, allow for once-daily dosing 1589.
Muscarinic Receptor Antagonists
These drugs block muscarinic receptors in the airways, reducing bronchoconstriction caused by the parasympathetic nervous system. They are also divided into:
- Short-acting muscarinic antagonists (SAMAs).
- Long-acting muscarinic antagonists (LAMAs), such as tiotropium, glycopyrronium, aclidinium, and umeclidinium, which are commonly used for maintenance therapy in COPD 159.
Xanthines
Xanthines, such as theophylline, are less commonly used due to their narrow therapeutic window and side effect profile. They act by inhibiting phosphodiesterase, leading to bronchodilation 15.
Combination and Dual Bronchodilator Therapies
Combining bronchodilators from different classes, such as LABA/LAMA combinations, provides greater symptom control and reduces exacerbations compared to monotherapy. Fixed-dose combinations are now standard in COPD management, and triple inhalers (LABA/LAMA/ICS) are also available for patients with more severe disease 569.
New and Emerging Bronchodilator Classes
Research is ongoing to develop new bronchodilator classes to address limitations of current therapies. Potential new classes under investigation include:
- Selective phosphodiesterase inhibitors
- Bitter-taste receptor agonists
- E-prostanoid receptor 4 agonists
- Rho kinase inhibitors
- Calcilytics
- Peroxisome proliferator-activated receptor-γ agonists
- Relaxin receptor 1 agonists
- Soluble guanylyl cyclase activators
- Pepducins
Most of these are still in preclinical development, and their future clinical use remains to be determined 25.
Classification by Duration of Action
Bronchodilators are also classified by how long they act:
- Short-acting agents are used for quick symptom relief (rescue therapy).
- Long-acting agents are used for ongoing maintenance therapy, with once-daily dosing preferred to improve adherence 159.
Conclusion
Bronchodilators are classified into three main groups: β2-agonists, muscarinic antagonists, and xanthines, with further subdivisions based on duration of action. Combination therapies, especially LABA/LAMA, are now standard for COPD, and new drug classes are being explored to further optimize bronchodilation. The classification and use of bronchodilators continue to evolve as new therapies and combinations are developed 12569.
Sources and full results
Most relevant research papers on this topic