Examples of Long-Acting Muscarinic Antagonists (LAMAs)
The currently available LAMAs for COPD treatment include tiotropium, aclidinium bromide, glycopyrronium bromide (also called glycopyrrolate), and umeclidinium bromide. 1, 2, 3, 4, 5
Currently Approved LAMAs
First-Generation LAMA
- Tiotropium bromide was the first LAMA developed and remains the most extensively studied, available as both a dry powder inhaler (HandiHaler) delivering 18 mcg and a soft mist inhaler (Respimat) delivering 5 mcg per dose 1, 2, 4, 6
Newer-Generation LAMAs
- Aclidinium bromide is a newer LAMA with approximately 6% systemic bioavailability, which minimizes systemic anticholinergic effects 7, 4, 8, 5
- Glycopyrronium bromide (also known as glycopyrrolate or NVA-237) provides once-daily dosing at 50 mcg with rapid onset of action that is faster than tiotropium 4, 6, 8, 9, 5
- Umeclidinium bromide delivers 62.5 mcg of umeclidinium per dose and is available both as monotherapy and in fixed-dose combination products 3, 4, 5
Mechanism of Action
- All LAMAs produce bronchodilation by competitively and reversibly blocking muscarinic M2 and M3 receptors, with greater functional selectivity for M3 receptors on bronchial smooth muscle, resulting in inhibition of acetylcholine release and sustained bronchodilation lasting longer than 24 hours 1, 7, 10, 2, 3
Clinical Equivalence
- Network meta-analysis demonstrates that all currently available LAMAs are equally effective in preventing moderate-to-severe COPD exacerbations, with no statistically significant differences among them for this outcome 8
- All LAMAs provide similar clinical benefits in improving lung function, reducing dyspnea, decreasing exacerbation risk, and improving quality of life according to major respiratory societies 11, 8, 9