Inhaled (Asthma) Medications
Summary Table of Inhaled Asthma Medications
| Generic Name | Trade Name | Drug Class | Indication |
|---|---|---|---|
| Budesonide | Pulmicort | Inhaled Corticosteroid (ICS) | Long-term control of asthma |
| Fluticasone | Flixotide | Inhaled Corticosteroid (ICS) | Long-term control of asthma |
| Salmeterol | Serevent | Long-Acting Beta-Agonist (LABA) | Long-term bronchodilation |
| Formoterol | Foradil | Long-Acting Beta-Agonist (LABA) | Long-term bronchodilation |
| Tiotropium | Spiriva | Long-Acting Muscarinic Antagonist | Long-term maintenance of asthma and COPD |
| Montelukast | Singulair | Leukotriene Receptor Antagonist | Reduces bronchoconstriction and inflammation |
| Albuterol | Ventolin | Short-Acting Beta-Agonist (SABA) | Rapid relief of bronchospasm |
| Ipratropium | Atrovent | Short-Acting Muscarinic Antagonist | Short-term bronchodilation |
| Fluticasone/Salmeterol | Advair, Seretide | ICS/LABA Combination | Long-term control of asthma |
| Budesonide/Formoterol | Symbicort | ICS/LABA Combination | Long-term control of asthma |
| Fluticasone/Umeclidinium/Vilanterol | Trelegy Ellipta | ICS/LAMA/LABA Combination | Long-term maintenance of asthma and COPD |
Explanation of Drug Classes and Indications
- Inhaled Corticosteroids (ICS):
- Purpose: Reduce inflammation in the airways, decrease mucus production, and improve responsiveness to beta-agonists.
- Examples: Budesonide (Pulmicort), Fluticasone (Flixotide)
- Indication: Used for long-term control and prevention of asthma symptoms.
- Long-Acting Beta-Agonists (LABA):
- Purpose: Provide sustained bronchodilation by stimulating beta-2 adrenergic receptors.
- Examples: Salmeterol (Serevent), Formoterol (Foradil)
- Indication: Used for long-term maintenance of asthma; always combined with ICS for asthma to prevent increased risk of asthma-related deaths.
- Long-Acting Muscarinic Antagonists (LAMA):
- Purpose: Block muscarinic receptors to reduce bronchoconstriction and mucus production.
- Examples: Tiotropium (Spiriva)
- Indication: Used for long-term maintenance treatment of asthma and COPD.
- Leukotriene Receptor Antagonists:
- Purpose: Block leukotrienes, which cause bronchoconstriction and inflammation.
- Examples: Montelukast (Singulair)
- Indication: Adjunct therapy for reducing bronchoconstriction and inflammation in asthma.
- Short-Acting Beta-Agonists (SABA):
- Purpose: Provide quick relief from bronchospasm by relaxing bronchial smooth muscle.
- Examples: Albuterol (Ventolin)
- Indication: Used for rapid relief of acute asthma symptoms and prevention of exercise-induced bronchospasm.
- Short-Acting Muscarinic Antagonists (SAMA):
- Purpose: Block muscarinic receptors to provide short-term bronchodilation.
- Examples: Ipratropium (Atrovent)
- Indication: Used in combination with SABA for acute exacerbations of asthma.
- Combination Inhalers (ICS/LABA):
- Purpose: Combine anti-inflammatory effects of ICS with the bronchodilation effects of LABA.
- Examples: Fluticasone/Salmeterol (Advair, Seretide), Budesonide/Formoterol (Symbicort)
- Indication: For long-term control of asthma in patients not adequately controlled on ICS alone.
- Combination Inhalers (ICS/LAMA/LABA):
- Purpose: Combine the effects of ICS, LAMA, and LABA for comprehensive asthma management.
- Examples: Fluticasone/Umeclidinium/Vilanterol (Trelegy Ellipta)
- Indication: For long-term maintenance treatment of asthma and COPD in patients requiring triple therapy.
Introduction
Asthma management relies heavily on inhaled medications to control symptoms and prevent exacerbations. This guide focuses on the pharmacodynamics and pharmacokinetics of key inhaled medications used in asthma treatment.
Inhaled Corticosteroids (ICS)
1. Budesonide (Pulmicort)
- Dose to Treat: 200-400 mcg twice daily.
- Pharmacodynamics (What the Drug Does to the Body):
- Reduces airway inflammation.
- Decreases mucus production.
- Enhances responsiveness of beta-adrenergic receptors.
- Pharmacokinetics (What the Body Does to the Drug):
- Absorbed in the lungs with minimal systemic absorption.
- Metabolized by the liver via CYP3A4.
- Excreted primarily in urine.
2. Fluticasone (Flixotide)
- Dose to Treat: 100-250 mcg twice daily.
- Pharmacodynamics:
- Controls chronic inflammation.
- Reduces bronchial hyperresponsiveness.
- Decreases frequency of asthma symptoms and exacerbations.
- Pharmacokinetics:
- Low systemic absorption due to high first-pass metabolism.
- Metabolized by the liver via CYP3A4.
- Excreted in feces and urine.
Long-Acting Beta-Agonists (LABA)
3. Salmeterol
- Dose to Treat: 50 mcg twice daily.
- Pharmacodynamics:
- Provides long-term bronchodilation.
- Relaxes bronchial smooth muscle by stimulating beta-2 adrenergic receptors.
- Pharmacokinetics:
- Absorbed through the lungs with a slow onset of action.
- Metabolized by the liver.
- Excreted primarily in feces.
4. Formoterol
- Dose to Treat: 12 mcg twice daily.
- Pharmacodynamics:
- Provides rapid and long-lasting bronchodilation.
- Relaxes bronchial smooth muscle quickly due to faster onset.
- Pharmacokinetics:
- Absorbed through the lungs.
- Metabolized by the liver.
- Excreted in urine and feces.
Long-Acting Muscarinic Antagonists (LAMA)
5. Tiotropium (Spiriva)
- Dose to Treat: One inhalation daily.
- Pharmacodynamics:
- Provides sustained bronchodilation.
- Blocks muscarinic receptors in the airways, reducing bronchoconstriction and mucus secretion.
- Pharmacokinetics:
- Absorbed in the lungs with prolonged action.
- Minimally metabolized; excreted unchanged in urine.
Leukotriene Receptor Antagonists
6. Montelukast (Singulair)
- Dose to Treat: 4 mg (children 2-5 years), 5 mg (children 6-14 years) orally once daily.
- Pharmacodynamics:
- Reduces bronchoconstriction and inflammation.
- Blocks leukotriene receptors, preventing leukotriene-mediated effects.
- Pharmacokinetics:
- Absorbed orally.
- Metabolized extensively by the liver.
- Excreted in bile and feces.
Short-Acting Beta-Agonists (SABA)
7. Albuterol (Ventolin)
- Dose to Treat: 2 puffs as needed.
- Pharmacodynamics:
- Provides rapid relief of bronchospasm.
- Stimulates beta-2 adrenergic receptors to relax bronchial smooth muscle.
- Pharmacokinetics:
- Absorbed in the lungs with a quick onset.
- Partially metabolized by the liver.
- Excreted in urine.
Short-Acting Muscarinic Antagonists (SAMA)
8. Ipratropium (Atrovent)
- Dose to Treat: 2 puffs 3-4 times daily.
- Pharmacodynamics:
- Provides short-term bronchodilation.
- Blocks muscarinic receptors, reducing bronchoconstriction.
- Pharmacokinetics:
- Absorbed in the lungs.
- Minimally metabolized.
- Excreted unchanged in urine.
Combination Inhalers
9. Fluticasone/Salmeterol (Advair, Seretide)
- Dose to Treat: One inhalation twice daily.
- Pharmacodynamics:
- Reduces inflammation (Fluticasone) and provides long-term bronchodilation (Salmeterol).
- Pharmacokinetics:
- Fluticasone: Minimal systemic absorption, metabolized by CYP3A4.
- Salmeterol: Absorbed through the lungs, metabolized by the liver.
10. Budesonide/Formoterol (Symbicort)
- Dose to Treat: Two inhalations twice daily.
- Pharmacodynamics:
- Combines anti-inflammatory effects (Budesonide) with rapid and long-lasting bronchodilation (Formoterol).
- Pharmacokinetics:
- Budesonide: Metabolized by CYP3A4, excreted in urine.
- Formoterol: Metabolized by the liver, excreted in urine and feces.
11. Trelegy Ellipta (Fluticasone/Umeclidinium/Vilanterol)
- Dose to Treat: One inhalation once daily.
- Pharmacodynamics:
- Reduces inflammation (Fluticasone), provides sustained bronchodilation (Umeclidinium), and long-term bronchodilation (Vilanterol).
- Pharmacokinetics:
- Fluticasone: Low systemic absorption, metabolized by CYP3A4.
- Umeclidinium: Minimal metabolism, excreted unchanged in urine.
- Vilanterol: Absorbed in the lungs, metabolized by the liver.
Conclusion
Understanding the pharmacodynamics and pharmacokinetics of inhaled asthma medications helps pediatric residents optimize asthma management, ensuring effective symptom control and preventing exacerbations. This guide provides a concise reference for the most commonly used inhaled drugs in asthma treatment.