Nurses Compass
Drug Guide
Salmeterol Xinafoate
Classification
Therapeutic: Bronchodilator (long-acting beta2-adrenergic agonist)
Pharmacological: Beta2-adrenergic receptor agonist
FDA Approved Indications
- Chronic obstructive pulmonary disease (COPD)
- Asthma (as adjunct therapy)
Mechanism of Action
Salmeterol binds to beta2-adrenergic receptors on airway smooth muscle, activating adenyl cyclase, which increases cyclic AMP levels, leading to bronchodilation.
Dosage and Administration
Adult: Usually 50 mcg twice daily via Diskus inhaler or 25 mcg twice daily via AccuNeb nebulizer, as directed by a physician.
Pediatric: Use in children aged 4 years and older as prescribed; dosing depends on formulation and age.
Geriatric: No specific dosage adjustment required, but monitor for development of adverse effects.
Renal Impairment: No specific adjustment recommended.
Hepatic Impairment: Use with caution; no specific dosing guidelines established.
Pharmacokinetics
Absorption: Rapid absorption from lungs.
Distribution: Widely distributed in tissues; protein binding approximately 64%.
Metabolism: Extensively metabolized by hepatic CYP3A4 enzyme.
Excretion: Excreted primarily in feces; minimal renal excretion.
Half Life: Approximately 3.5 hours in plasma.
Contraindications
- Hypersensitivity to salmeterol or any component.
- Concurrent use with other long-acting beta2-adrenergic agonists in some circumstances.
Precautions
- Use with caution in patients with cardiac arrhythmias, hypertension, or seizure disorders.
- Not for use as a rescue inhaler; risks of asthma-related death noted in some studies.
- Can precipitate hypokalemia, monitor potassium levels during therapy.
Adverse Reactions - Common
- Headache (Common)
- Throat irritation (Common)
- Musculoskeletal pain (Common)
Adverse Reactions - Serious
- Severe allergic reactions (rash, itching, swelling, difficulty breathing) (Rare)
- Cardiac arrhythmias (Rare)
- Hypokalemia (Uncommon)
Drug-Drug Interactions
- Other sympathomimetics, MAO inhibitors, tricyclic antidepressants, corticosteroids (risk of hypokalemia and cardiac effects)
Drug-Food Interactions
- No significant interactions reported
Drug-Herb Interactions
- No well-established interactions.
Nursing Implications
Assessment: Monitor respiratory status, heart rate, blood pressure, and potassium levels.
Diagnoses:
- Ineffective airway clearance,
- Risk for adverse cardiac events
Implementation: Administer via inhaler/systemic as prescribed, educate patient on correct inhaler technique, monitor for side effects.
Evaluation: Assess improvement in breathing, reduction in symptoms, and monitor for adverse effects.
Patient/Family Teaching
- Use inhaler exactly as prescribed.
- Report any signs of worsening symptoms or adverse reactions.
- Ensure understanding that this is not a rescue medication.
- Wash mouth after inhalation to prevent oral candidiasis.
Special Considerations
Black Box Warnings:
- Severe asthma-related events and death have been reported with LABA use; should not be used without an inhaled corticosteroid in asthma.
- Risk of asthma-related death appears increased when used as monotherapy in asthma.
Genetic Factors: Limited data; pharmacogenomic testing not routinely required.
Lab Test Interference: No significant interference reported with laboratory tests.
Overdose Management
Signs/Symptoms: Nausea, vomiting, headache, tachycardia, hypokalemia.
Treatment: Discontinue salmeterol, provide supportive care, monitor vital signs and serum potassium, administer potassium as needed, and provide cardiovascular support if indicated.
Storage and Handling
Storage: Store at room temperature away from moisture, heat, and direct sunlight.
Stability: Stable under recommended storage conditions until the expiration date.