Overview
Salmeterol is a long-acting beta2-adrenergic agonist (LABA) bronchodilator used for maintenance treatment of asthma and COPD. It works by relaxing airway smooth muscle to improve airflow and prevent bronchospasm. Salmeterol is always combined with an inhaled corticosteroid in asthma treatment to reduce the risk of serious asthma-related events.
Mechanism of Action
Salmeterol is a selective long-acting beta2-adrenergic receptor agonist that stimulates adenylate cyclase, increasing intracellular cyclic AMP. This leads to relaxation of bronchial smooth muscle, inhibition of mast cell mediator release, and reduced microvascular permeability, resulting in bronchodilation and protection against bronchoconstriction.
Indications
- Maintenance treatment of asthma in patients aged 4 years and older (in combination with an inhaled corticosteroid)
- Prevention of exercise-induced bronchospasm in patients aged 4 years and older
- Maintenance treatment of airflow obstruction in patients with COPD, including chronic bronchitis and emphysema
Common Doses
- 50 mcg per inhalation
- Standard strength: 50 mcg
Dosage
For asthma and COPD: 1 inhalation (50 mcg) twice daily (approximately 12 hours apart). For exercise-induced bronchospasm: 1 inhalation at least 30 minutes before exercise (additional doses should not be used for at least 12 hours). Should not be used more frequently than twice daily.
Black Box Warning
Increased risk of asthma-related death (black box warning)
Contraindications
- Primary treatment of status asthmaticus or other acute episodes of asthma or COPD where intensive measures are required
- Severe hypersensitivity to milk proteins or demonstrated hypersensitivity to salmeterol or any excipients
Side Effects
- Headache
- Tremor
- Palpitations
- Tachycardia
- Throat irritation
- Cough
- Upper respiratory tract infection
- Muscle cramps
- Nervousness
- Dizziness
- Paradoxical bronchospasm
- Hypersensitivity reactions
Interactions
- Beta-blockers may reduce effectiveness and cause severe bronchospasm
- Monoamine oxidase inhibitors and tricyclic antidepressants may potentiate cardiovascular effects
- Other sympathomimetic agents may increase cardiovascular effects
- Diuretics may increase risk of hypokalemia
- QT-prolonging drugs may increase risk of arrhythmias
Counseling Points
- Use regularly twice daily, not for acute symptoms
- Rinse mouth with water after each use to prevent oral thrush
- Do not exceed prescribed dose
- Keep quick-relief inhaler available for acute symptoms
- Notify healthcare provider if asthma worsens or need for quick-relief inhaler increases
- Do not stop using without consulting healthcare provider