Usage
- Arformoterol is prescribed for the long-term, twice-daily (morning and evening) maintenance treatment of bronchoconstriction in patients with chronic obstructive pulmonary disease (COPD), including chronic bronchitis and emphysema. It is not indicated for the treatment of asthma or acute episodes of bronchospasm.
- Pharmacological Classification: Long-acting beta2-adrenergic agonist (LABA), Bronchodilator
- Mechanism of Action: Arformoterol relaxes the smooth muscles in the airways, leading to bronchodilation and improved airflow to the lungs.
Alternate Names
- (R,R)-formoterol
- Brand Name: Brovana
How It Works
- Pharmacodynamics: Arformoterol acts as a selective agonist at beta2-adrenergic receptors, primarily in the lungs. This stimulation activates intracellular signaling pathways that lead to smooth muscle relaxation and bronchodilation.
- Pharmacokinetics:
- Absorption: Administered via nebulization, arformoterol is rapidly absorbed into the systemic circulation.
- Metabolism: Primarily metabolized in the liver.
- Elimination: Primarily eliminated via renal excretion.
- Mode of Action: Binds to beta2-adrenergic receptors on airway smooth muscle cells, initiating a cascade of intracellular events culminating in bronchodilation.
- Receptor Binding: Selective agonist at beta2-adrenergic receptors. Minimal activity at beta1 receptors, therefore reducing cardiovascular side effects compared with non-selective beta-agonists.
- Elimination Pathways: Primarily renal excretion; some hepatic metabolism.
Dosage
Standard Dosage
Adults:
- 15 mcg administered twice daily (morning and evening) by nebulization.
- The total daily dose should not exceed 30 mcg.
Children:
- Use and dose must be determined by a doctor; safety and efficacy have not been established in pediatric patients under 18.
Special Cases:
- Elderly Patients: No dose adjustment is typically required.
- Patients with Renal Impairment: No dose adjustment required.
- Patients with Hepatic Dysfunction: No dose adjustment required, but use with caution and close monitoring due to potential for prolonged systemic exposure.
- Patients with Comorbid Conditions: Use with caution in patients with cardiovascular disease, diabetes, hyperthyroidism, hypokalemia, seizures, and those taking other medications.
Clinical Use Cases
- Arformoterol is not recommended for intubation, surgical procedures, mechanical ventilation, intensive care unit (ICU) use, or emergency situations. Its long-acting nature makes it unsuitable for acute management. Short-acting bronchodilators are preferred for these settings.
Dosage Adjustments
- Dosage modifications may be necessary based on individual patient response and tolerability.
Side Effects
Common Side Effects
- Headache, dizziness, nervousness, tremor, back pain, chest pain, diarrhea, leg cramps, skin rash, swelling in the legs, stuffy nose, flu-like symptoms, dry mouth.
Rare but Serious Side Effects
- Worsening breathing problems (paradoxical bronchospasm), severe allergic reactions (hives, swelling of face, lips, tongue, or throat), fast or irregular heartbeat, chest pain, high blood sugar, low potassium levels.
Long-Term Effects
- Potential long-term effects are not well-established, but chronic use of beta2-agonists has been linked to a possible increased risk of cardiovascular issues.
Adverse Drug Reactions (ADR)
- Paradoxical bronchospasm, severe allergic reactions, cardiac arrhythmias, hypokalemia.
Contraindications
- Hypersensitivity to arformoterol, formoterol, or any component of the product.
- Use of a LABA without an inhaled corticosteroid is contraindicated in asthma patients.
- Asthma.
Drug Interactions
- Beta-blockers, other bronchodilators, certain antidepressants (MAOIs, TCAs), drugs that prolong the QT interval (e.g. some antipsychotics, some antibiotics), diuretics (potassium loss), digoxin.
Pregnancy and Breastfeeding
- Pregnancy: No adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus.
- Breastfeeding: No recommendation from the manufacturer regarding use during lactation. While very little is expected to be excreted into breast milk, the safety of the drug for the nursing infant is not established.
Drug Profile Summary
- Mechanism of Action: Relaxes airway smooth muscle by stimulating beta2-adrenergic receptors.
- Side Effects: Headache, tremor, nervousness, worsening of breathing, allergic reactions, cardiac effects, hypokalemia.
- Contraindications: Hypersensitivity, asthma without concurrent ICS, acute bronchospasm.
- Drug Interactions: Beta-blockers, MAOIs, TCAs, QT-prolonging drugs, diuretics, other bronchodilators.
- Pregnancy & Breastfeeding: Use with caution; potential fetal risks; limited data on breastfeeding safety.
- Dosage: 15 mcg by nebulization twice daily; max 30 mcg/day.
- Monitoring Parameters: Pulmonary function tests, blood pressure, heart rate, potassium levels, blood glucose.
Popular Combinations
- Arformoterol is not typically used in combination with other inhaled long-acting bronchodilators. Short-acting bronchodilators (e.g., albuterol) may be used as rescue medication for acute symptoms.
Precautions
- Pre-existing medical conditions: Assess patients for cardiac disease, diabetes, hyperthyroidism, hypokalemia, and seizures.
- Pregnant women: Weigh benefits against potential risks to the fetus.
- Breastfeeding mothers: Limited data available; consider the infant’s potential exposure.
- Children & Elderly: Safety and efficacy in pediatric patients not established; no specific precautions for the elderly.
- Lifestyle Considerations: Monitor for potential drug interactions with alcohol, smoking, and diet.
FAQs (Frequently Asked Questions)
A: The standard adult dose is 15 mcg via nebulization twice daily (morning and evening), not to exceed 30 mcg per day. Pediatric dosing is not established.
A: No, arformoterol is not indicated for the treatment of asthma. Studies have shown an increased risk of asthma-related death with LABAs like arformoterol when used without an inhaled corticosteroid.
A: Arformoterol should be administered via nebulization using a standard jet nebulizer connected to an air compressor. It should not be swallowed or injected.
A: Common side effects include headache, tremor, nervousness, back pain, chest pain, diarrhea, leg cramps, skin rash, swelling in the legs, stuffy nose, and flu-like symptoms.
A: Paradoxical bronchospasm is a serious side effect. Discontinue arformoterol immediately and seek medical attention.
A: Arformoterol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Consult with a specialist.
A: Yes, arformoterol can interact with several medications, including beta-blockers, certain antidepressants (MAOIs, TCAs), QT-prolonging drugs, and other bronchodilators.
A: Concurrent use of arformoterol with other long-acting beta2-agonists is not recommended. Short-acting bronchodilators may be used as needed for acute symptoms.
A: Yes, no dosage adjustment is needed for patients with renal impairment.
A: Store unopened vials in the foil pouch in the refrigerator. Unopened pouches may be stored at room temperature for up to six weeks. Once a vial is opened, use immediately. Discard after six weeks or the expiry date if stored at room temperature.
