Asthma and COPD: In-Depth Notes

Asthma Overview

• Asthma is a chronic disorder characterized by airway obstruction due to bronchoconstriction (tightening of smooth muscles around the airways) and airway inflammation.
• Symptoms occur in episodes or attacks triggered by allergens, cold air, dry air, and other irritants.
• In susceptible individuals, tissue conditions for asthma persist, causing symptom episodes.

Chronic Obstructive Pulmonary Disease (COPD)

• COPD includes chronic bronchitis and emphysema.
  • Chronic Bronchitis: Persistent inflammation leading to swollen airway mucous membranes, thick mucus, and difficulty in airflow.
  • Emphysema: Damage to alveoli leading to loss of elasticity, making exhalation harder.
• Both conditions are progressive and worsen over time, primarily caused by cigarette smoking and vaping.

Drug Therapies for Asthma and COPD

• Bronchodilators: Drugs that relax smooth muscles around airways, allowing enlargement of the lumen and improving airflow. They do not affect inflammation.
• Types of Bronchodilators:
  • Beta-2 Adrenergic Agonists: Help asthma by binding to beta-2 receptors, triggering muscle relaxation through increased cyclic adenosine monophosphate (cAMP).
  • Cholinergic Antagonists: Block the parasympathetic nervous system, allowing natural epinephrine and norepinephrine to induce bronchodilation.

Common Bronchodilators

• Short-acting: Albuterol, Benelin
• Long-acting: Salmeterol, Formoterol
• Cholinergic Antagonists: Ipratropium (Atrovent), Tiotropium (Spiriva)

Administration and Side Effects

• Systemic Effects of Bronchodilators:
  • Rapid heart rate, changes in blood pressure, nervousness, tremors, difficulty sleeping, bad taste; rinse mouth after use.
  • Other effects: urinary retention, blurred vision, dry mouth, headache.

Inhaler Techniques

• Types of Inhalers:
  1. Metered Dose Inhalers (MDI): Release drugs as a fine liquid spray.
  2. Dry Powder Inhalers (DPI): Deliver drugs as fine powders.
  3. Soft Mist Inhalers (SMI): Deliver drugs in a fine mist.
• Correct technique is essential for efficacy; incorrect methods can lead to reduced drug delivery.
• Use of Spacers: Helpful for patients who struggle with inhaler technique.
• If a patient must take multiple inhalers, administer bronchodilator first for optimal effect.

Corticosteroids for Inflammation

• Inhaled Corticosteroids reduce bronchial inflammation effectively:
  • Interfere with protein synthesis in inflammatory cells.
• Common inhaled corticosteroids include Fluticasone (Flovent) and Beclomethasone (Acrylocort).
• Combination medications (e.g., Advair, Symbicort) contain both bronchodilators and corticosteroids for enhanced management of asthma and COPD.

Teaching Priorities for Patients

• Long-acting medications must be taken consistently, even if symptoms are not present, as they prevent attacks.
• Short-acting bronchodilators should be used for acute attacks, not long-acting agents.
• Encourage patients to maintain oral hygiene to prevent bad taste and reduce the risk of thrush post-inhalation.
• Advise about refill stages: obtain a new inhaler five days before running out.

Mucolytics

• Acetylcysteine: Most often delivered with a nebulizer; can also be taken orally with a strong odor that may cause nausea or vomiting in some patients.