salmeterol

Salmeterol is a long-acting beta2-adrenergic agonist (LABA) used as maintenance bronchodilator therapy for asthma and chronic obstructive pulmonary disease (COPD). It provides prolonged bronchodilation for up to about 12 hours and is not intended for relief of acute bronchospasm. It is delivered by inhalation, most commonly as a dry powder inhaler (Diskus/Accuhaler) and in combination products with an inhaled corticosteroid (ICS).

Mechanism of action is through selective activation of beta2 receptors in bronchial smooth muscle, which causes relaxation and bronchodilation. The onset of salmeterol is slower than short-acting beta agonists, but the effect lasts long enough to support twice-daily dosing.

Indications and usage vary by disease. In asthma, salmeterol is recommended only when used in combination with an inhaled corticosteroid; it should not be used as monotherapy due to an increased risk of asthma-related death. In COPD, salmeterol is approved for maintenance treatment to reduce symptoms and exacerbations, often in combination with ICS or other COPD therapies.

Dosage and formulations typically involve one inhalation of 50 mcg twice daily, with instructions to avoid using it for acute symptom relief. Patients should be instructed to use a rescue inhaler for immediate symptoms.

Side effects commonly include headache, tremor, tachycardia, throat irritation, and pharyngitis. Serious risks include cardiovascular effects and, in asthma, an increased risk of asthma-related death when used without an accompanying ICS. Salmeterol should be used with caution in patients with cardiovascular disorders, diabetes, or thyroid disease.

Brand names include Serevent, and combination products include Seretide/Advair.