respiratory bronchodilator antimuscarinic
Antimuscarinics bronchodilate by blocking vagal bronchoconstriction rather than stimulating dilation.
They are the foundation maintenance bronchodilators in COPD and adjunct therapy in asthma.
These medications are a respiratory application of muscarinic receptor blockade.
Receptor Blocked
(see Autonomic Antimuscarinics)
Normal Physiology
Drug Effect
Net effect:
Primary therapy:
Adjunct therapy:
Often combined with:
| Class | Onset | Duration | Clinical Role |
|---|---|---|---|
| SAMA | ~15 min | ~6 hr | Exacerbation adjunct |
| LAMA | 30–60 min | 24+ hr | Maintenance therapy |
| Effect | Mechanism |
|---|---|
| Dry mouth | Reduced secretions |
| Urinary retention | Bladder detrusor inhibition |
| Blurred vision | Ocular exposure |
| Constipation | GI smooth muscle inhibition |
Minimal systemic absorption due to inhaled route.
COPD is primarily cholinergic-mediated bronchoconstriction → LAMA therapy is foundational treatment
| Drug Class | Mechanism | Best Disease Target |
|---|---|---|
| β2 agonists | Stimulate dilation | Asthma |
| Antimuscarinics | Block constriction | COPD |