Respiratory Medications

• Respiratory medications encompass a wide range of drugs used to treat various respiratory conditions
• These medications aim to improve airflow, reduce inflammation, manage symptoms, and prevent complications

Bronchodilators

• Bronchodilators relax the smooth muscles surrounding the airways, widening them and easing breathing
• They are commonly used in conditions like asthma and chronic obstructive pulmonary disease (COPD)

Beta-Agonists

• Beta-agonists stimulate beta-adrenergic receptors in the lungs, leading to bronchodilation
• Short-acting beta-agonists (SABAs): Provide quick relief during acute bronchospasm
  • Examples: albuterol, levalbuterol
  • Administered via inhalers or nebulizers for rapid onset
• Long-acting beta-agonists (LABAs): Offer sustained bronchodilation for long-term control
  • Examples: salmeterol, formoterol
  • Typically used in combination with inhaled corticosteroids due to potential risks when used alone

Anticholinergics

• Anticholinergics block acetylcholine receptors in the airways, reducing bronchoconstriction and mucus production
• Short-acting anticholinergics: Provide relief during acute exacerbations
  • Example: ipratropium bromide
  • Often combined with SABAs for enhanced bronchodilation
• Long-acting anticholinergics (LAMAs): Offer prolonged bronchodilation for maintenance therapy
  • Examples: tiotropium, umeclidinium
  • Provides sustained relief in COPD management

Methylxanthines

• Methylxanthines, such as theophylline, are bronchodilators with anti-inflammatory properties
• Mechanism of action involves phosphodiesterase inhibition and adenosine receptor antagonism
• Narrow therapeutic index requires careful monitoring of drug levels to avoid toxicity
• Use has declined due to the availability of safer and more effective alternatives

Inhaled Corticosteroids (ICS)

• Inhaled corticosteroids reduce inflammation in the airways, decreasing swelling and mucus production
• Commonly used for long-term control of asthma and COPD
• Examples: budesonide, fluticasone, beclomethasone
• Administered via inhalers or nebulizers for direct delivery to the lungs
• Long-term use can lead to side effects such as oral thrush and hoarseness; rinsing the mouth after inhalation can help prevent these

Combination Inhalers

• Combination inhalers contain two or more medications in a single device, improving convenience and adherence
• Common combinations include:
  • ICS/LABA: Combines an inhaled corticosteroid with a long-acting beta-agonist
    • Examples: fluticasone/salmeterol, budesonide/formoterol
    • Used for long-term control of asthma and COPD
  • LAMA/LABA: Combines a long-acting muscarinic antagonist with a long-acting beta-agonist
    • Examples: umeclidinium/vilanterol, tiotropium/olodaterol
    • Used for COPD management
  • ICS/LAMA/LABA: Combines an inhaled corticosteroid, a long-acting muscarinic antagonist, and a long-acting beta-agonist
    • Example: budesonide/glycopyrrolate/formoterol
    • Used for COPD management

Leukotriene Modifiers

• Leukotriene modifiers block the action of leukotrienes, inflammatory mediators that contribute to airway constriction and mucus production
• Used for long-term control of asthma, particularly in patients with allergic or exercise-induced asthma
• Examples: montelukast, zafirlukast
• Administered orally

Mast Cell Stabilizers

• Mast cell stabilizers prevent the release of inflammatory substances from mast cells, reducing airway inflammation and hyperreactivity
• Used for prophylactic treatment of asthma, particularly in children and patients with exercise-induced asthma
• Example: cromolyn sodium
• Administered via inhaler or nebulizer

Expectorants and Mucolytics

• Expectorants help to loosen and thin mucus in the airways, making it easier to cough up
  • Example: guaifenesin
  • Available over-the-counter
• Mucolytics break down the chemical bonds in mucus, reducing its viscosity and promoting expectoration
  • Examples: acetylcysteine, dornase alfa
  • Acetylcysteine is administered via nebulizer and can also be used to protect the kidneys during the administration of radiographic contrast dye, and to treat paracetamol overdose
  • Dornase alfa is used in cystic fibrosis to break down DNA in mucus and improve lung function

Antitussives

• Antitussives suppress the cough reflex, providing relief from coughing
• Used for symptomatic treatment of dry, nonproductive coughs
• Examples:
  • Opioids: codeine, hydrocodone (act centrally to suppress cough)
  • Non-opioids: dextromethorphan (acts centrally), benzonatate (acts peripherally)
• Use is generally discouraged in productive coughs, as it can impair airway clearance

Oxygen Therapy

• Oxygen therapy provides supplemental oxygen to patients with hypoxemia (low blood oxygen levels)
• Administered via nasal cannula, face mask, or mechanical ventilation
• Used to improve oxygen saturation and reduce the workload on the heart and lungs
• Different delivery methods include:
  • Nasal Cannula: Delivers low-flow oxygen
  • Face Mask: Delivers higher concentrations of oxygen
  • Non-Invasive Ventilation (NIV): Provides ventilatory support without intubation
  • Mechanical Ventilation: Provides ventilatory support via an endotracheal tube or tracheostomy

Pulmonary Surfactants

• Pulmonary surfactants reduce surface tension in the alveoli, preventing alveolar collapse and improving lung compliance
• Used in premature infants with respiratory distress syndrome (RDS) to improve lung function
• Examples: beractant, calfactant
• Administered via endotracheal tube

Immunomodulators

• Immunomodulators modify the immune response to reduce inflammation and prevent exacerbations
• Used in severe asthma and other respiratory conditions
• Examples:
  • Omalizumab: Anti-IgE antibody that reduces allergic inflammation
  • Biologic therapies: Target specific inflammatory pathways in asthma

Considerations

• Delivery devices significantly impact drug delivery to the lungs
• Common devices include metered-dose inhalers (MDIs), dry powder inhalers (DPIs), and nebulizers
• MDIs require coordination between actuation and inhalation; spacers can improve drug delivery
• DPIs are breath-activated and require sufficient inspiratory flow
• Nebulizers convert liquid medication into a fine mist for inhalation, suitable for patients who cannot use MDIs or DPIs
• Patient education is crucial for proper medication use and adherence
• Patients should be educated on the correct use of inhalers and other devices, as well as the importance of adherence to prescribed regimens
• Regular monitoring of respiratory function is important to assess treatment response and adjust therapy as needed
• Pulmonary function tests (PFTs), such as spirometry, measure lung volumes and airflow rates
• Monitoring symptoms and exacerbation frequency can help guide treatment decisions