Salmeterol
Serevent Diskus
bronchodilator labainhaled (dry powder Diskus)Onset: 10–20 minutesDuration: 12 hours
Mechanism of Action
Long-acting selective beta-2 adrenergic agonist. Long lipophilic side chain anchors it to cell membrane near receptor, allowing sustained receptor activation. Increases cAMP → bronchial smooth muscle relaxation.
Dosing
Adult
Diskus: 50 mcg (1 inhalation) q12h. Not to be used more frequently.
Pediatric
≥4 years: 50 mcg q12h
Indications
- COPD maintenance therapy
- Asthma maintenance (always with ICS — NEVER monotherapy)
- Prevention of exercise-induced bronchospasm
- Nocturnal asthma symptoms
Contraindications
- Monotherapy in asthma (black box warning — increased asthma-related death)
- Acute bronchospasm (not a rescue drug)
- Hypersensitivity to salmeterol
Side Effects
- Tachycardia
- Tremor
- Hypokalemia
- Headache
- Throat irritation (dry powder)
Monitoring Parameters
- Heart rate
- Asthma control — must be used with ICS
- Peak flow / spirometry
- Serum potassium
Drug Interactions
- Beta-blockers (antagonism)
- MAOIs (cardiovascular potentiation)
- Non-potassium-sparing diuretics (hypokalemia)
- QT-prolonging drugs (additive risk)
Clinical Pearls
- BLACK BOX WARNING: increased risk of asthma-related death when used without ICS
- Always prescribed with inhaled corticosteroid in asthma
- NOT for acute rescue — onset is 10–20 minutes, used for maintenance only
- Combined with fluticasone in Advair (most commonly prescribed LABA/ICS combo)
- Duration (12 hr) allows BID dosing
Mnemonic
💡 Salmeterol: Slow Starter, 12-hour Maintenance — never Solo in asthma
NBRC High-Yield
- LABA — 12-hour duration, NOT a rescue inhaler
- Black box warning: NEVER use as monotherapy in asthma
- Must always be combined with ICS in asthma patients
- Available as Advair when combined with fluticasone
- Safe for COPD as monotherapy or with ICS