Labas

Long-acting beta-adrenergic agonists (LABAs) are a class of bronchodilators used in the maintenance treatment of obstructive airway diseases such as asthma and chronic obstructive pulmonary disease (COPD). LABAs activate beta-2 adrenergic receptors on airway smooth muscle, increasing cyclic AMP and producing prolonged relaxation of the airways. They are intended for regular, not immediate, symptom control and are not used as rescue medications for acute bronchospasm.

Common LABAs include salmeterol and formoterol, with newer agents such as vilanterol, indacaterol, and olodaterol. LABAs differ in onset and duration of action, with some providing rapid onset of bronchodilation and others offering once-daily dosing. In many inhalation formulations, LABAs are combined with other therapies to enhance disease control, such as inhaled corticosteroids or long-acting muscarinic antagonists.

In asthma, LABAs should be prescribed only in combination with an inhaled corticosteroid. Using a LABA alone in asthma has been associated with worse outcomes in some settings, historically leading to boxed warnings; current guidelines emphasize concurrent ICS use to improve safety and efficacy and to reduce exacerbations and symptoms in patients not adequately controlled by ICS alone.

In COPD, LABAs are a standard maintenance therapy and may be used alone or in combination with other agents such as LAMA or ICS, depending on disease severity and symptom burden. LABAs do not replace short-acting bronchodilators used for rescue relief.

Common adverse effects include tremor, tachycardia, and headaches; systemic effects are uncommon with inhaled therapy. Cautions include cardiovascular disease and potential drug interactions, and they should be used as directed by medical guidance.