Examples of Beta-Agonists and Long-Acting Bronchodilators
Short-acting β2-agonists (SABAs) include albuterol, levalbuterol, and pirbuterol, while long-acting β2-agonists (LABAs) include salmeterol and formoterol; long-acting muscarinic antagonists (LAMAs) include tiotropium, aclidinium, glycopyrronium, and umeclidinium. 1
Short-Acting β2-Agonists (SABAs)
The primary SABAs used in clinical practice are:
- Albuterol (salbutamol)
- Levalbuterol
- Pirbuterol
These medications provide rapid bronchodilation lasting 2-6 hours and serve as the treatment of choice for acute symptom relief and prevention of exercise-induced bronchoconstriction 1. SABAs work by relaxing airway smooth muscle and should be used on an as-needed basis rather than as regularly scheduled maintenance therapy 1.
Long-Acting β2-Agonists (LABAs)
The two main LABAs available are:
- Salmeterol
- Formoterol
These agents provide bronchodilation lasting at least 12 hours after a single dose 1. LABAs must never be used as monotherapy for asthma and should always be combined with inhaled corticosteroids 1. In COPD management, LABAs are recommended as first-line long-acting bronchodilators for symptom control 2.
Long-Acting Muscarinic Antagonists (LAMAs)
The available LAMAs include:
- Tiotropium bromide
- Aclidinium bromide
- Glycopyrronium bromide
- Umeclidinium bromide
LAMAs block parasympathetic-mediated bronchoconstriction and are particularly effective in COPD, where they may be preferred over LABAs for exacerbation prevention 2, 3.
Short-Acting Anticholinergics
- Ipratropium bromide is the primary short-acting muscarinic antagonist (SAMA), providing additive benefit when combined with SABAs in moderate to severe exacerbations 1, 3.
Additional Long-Acting Bronchodilators
- Sustained-release theophylline (a methylxanthine) provides mild to moderate bronchodilation but requires serum concentration monitoring and is considered alternative rather than preferred therapy 1.
Clinical Context
For COPD patients, the GOLD guidelines recommend initiating long-acting bronchodilators (either LABA or LAMA) over short-acting agents for maintenance therapy, with LABA/LAMA combinations showing superior outcomes in more severe disease 2. In asthma, SABAs remain the cornerstone of rescue therapy, while LABAs are added to inhaled corticosteroids when symptom control is inadequate on corticosteroids alone 1.