Drugs Acting on the Respiratory System

WEEK 7: Drugs Acting on the Respiratory System

Instructor Information:

  • Instructor: Margaret Myers MSN, RN

  • Course: NUR 140

  • Copyright: © 2023 by Elsevier, Inc. All rights reserved.

LEARNING OBJECTIVES

Oxygenation Objectives

  1. Nursing Process

    • Utilize the nursing process including respiratory and oxygenation assessment.

    • Identify potential nursing diagnoses as both cause and etiology of respiratory medication use and administration.

    • Plan and implement nursing interventions.

  2. Patient Education

    • Educate patients regarding medications used for oxygenation, focusing on inhalers and aerosolized medication administration devices.

    • Inform patients about side effects and adverse reactions of medication use, including when to contact healthcare providers.

  3. Adverse Reactions

    • Identify effective treatments for adverse reactions to respiratory medications.

    • Understand the application of certain respiratory medications in the treatment of these reactions.

  4. Nursing Role

    • Outline the nursing role in the administration of respiratory medications.

    • Evaluate patient responses to these treatments.

  5. Research Application

    • Apply evidence-based research when considering nursing implications for respiratory medications.

  6. Drug Comparisons

    • Compare and contrast antihistamines, decongestants, antitussives, and expectorants in terms of their effectiveness in improving oxygenation.

  7. Disease-Specific Drugs

    • Differentiate drug groups related to oxygenation improvement in diseases such as Chronic Obstructive Pulmonary Disease (COPD) and restrictive airway diseases, along with their desired effects.

ANATOMY OF THE RESPIRATORY SYSTEM

  • Bronchial Tree:

    • Comprises bronchi leading into bronchioles.

  • Other Structures:

    • Trachea, ribs, lungs (shown in an inside view).

    • Diaphragm plays a crucial role in breathing.

LOWER RESPIRATORY DISORDERS

  • Key Disorders:

    • Chronic Obstructive Pulmonary Disease (COPD)

      • Subtypes include:

      • Chronic bronchitis

      • Emphysema

      • Refractory asthma

    • Asthma

    • Cystic Fibrosis

PATHOPHYSIOLOGY OF COPD

Definition

  • COPD: An inflammatory condition affecting airways, lung parenchyma, and pulmonary vasculature.

Chronic Bronchitis Pathophysiology

  • Characterized by increased mucus production, bronchospasm, and fibrosis.

Emphysema Pathophysiology

  • Involves alveolar septal destruction leading to air trapping, decreased elastic tissue, and bronchial collapse.

ASTHMA

Definition

  • Asthma: An inflammatory disease of the lungs marked by reversible airway obstruction.

Characteristics

  • Airway inflammation, intermittent airflow obstruction, bronchial hyperresponsiveness, excessive mucus production.

Hallmark Symptoms

  • Intermittent dyspnea, cough, wheezing.

Common Triggers

  • Exercise, stress, cold air, certain foods, dust mites, pet dander, infections, molds, pollution, and pollen.

BRONCHODILATORS

Drug Classes

  1. Beta2-Adrenergic Agonists, e.g., albuterol sulfate (Ventolin, ProAir).

  2. Anticholinergics, e.g., ipratropium bromide (Atrovent).

  3. Methylxanthines, e.g., theophylline (Theo-Dur).

Beta2-Adrenergic Agonists

  • Therapeutic Action: Bronchodilation via stimulation of beta2 receptors.

  • Therapeutic Use: Treatment and prophylaxis of bronchospasm in obstructive airway disease.

  • Routes: Oral, inhaled (MDI, nebulizer).

  • Adverse Effects Include:

    • Fear, anxiety, tremors, restlessness, headache, sore throat, dizziness, nausea, palpitation, tachycardia, paradoxical bronchospasm, hypersensitivity reactions.

Mechanisms of Action

  • Sympathetic Nervous System Activation: Epinephrine release causes bronchodilation.

  • Cyclic AMP (cAMP): Key signaling molecule that relaxes bronchial smooth muscle.

  • Phosphodiesterase Enzyme: Inactivates cAMP, leading to bronchoconstriction.

Contraindications and Cautions

  • Contraindications: Tachydysrhythmias.

  • Cautions: Diabetes mellitus, hyperthyroidism, heart disease, hypertension, and angina.

  • Drug-Drug Interactions:

    1. Caution with medications that increase heart rate and blood pressure.

    2. Beta-adrenergic blockers may diminish the effectiveness of beta2-adrenergic agonists.

    3. Monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants could increase risks.

Patient Education for Beta2-Adrenergic Agonists

  • For exercise-induced asthma (EIA), use 30-60 minutes prior to physical exertion.

  • Maintain a log of exacerbation patterns and report any changes.

  • Caution against overuse; notify provider if side effects interfere with daily activities.

  • Avoid caffeine to minimize additional stimulant effects.

ANTIMEDIATORS AND ANTI-INFLAMMATORIES

Anticholinergic Bronchodilators

  • Drug: ipratropium bromide (Atrovent).

  • Action: Blocks muscarinic cholinergic receptors, promoting bronchodilation.

  • Uses: Maintenance treatment for bronchospasms associated with COPD.

  • Side Effects: Anticholinergic effects, nasal irritation, and palpitations.

Methylxanthines

  • Drug: Theophylline.

  • Action: Increases cAMP, promoting bronchodilation.

  • Therapeutic Range: 10-20 mcg/mL, toxicity at values greater than 20.

  • Side Effects: Dizziness, tachycardia, hypotension, seizures.

Anti-Inflammatory Agents

  1. Leukotriene Receptor Antagonists: montelukast (Singulair), zileuton, zafirlukast.

    • Action: Decreases inflammation by preventing leukotriene activation.

    • Use: Asthma, allergy prophylaxis.

  2. Inhaled Corticosteroids: fluticasone (Flovent), budesonide (Pulmicort).

    • Action: Prevent release of inflammatory mediators.

    • Use: Long-term management of chronic asthma and COPD.

Patient Education for Inhaled Corticosteroids

  • Use beta2-adrenergic agonists prior to inhaled corticosteroids, rinse the mouth post-use, and utilize a spacer to minimize oral thrush risk.

  • Monitor for and treat potential side effects, including throat irritation and fungal infections.

COMBINATION THERAPY

  • Drug: fluticasone propionate/salmeterol.

  • Uses: Treat asthma, maintain airflow in COPD, prevent exercise-induced bronchospasm.

  • Side Effects: Various depending on condition; monitoring needed for exacerbation.

ADMINISTRATION TECHNIQUES

Metered Dose Inhalers (MDIs)

  1. Shake inhaler vigorously before use.

  2. Position correctly in the mouth; exhale before inhaling the medication.

  3. Inhale slowly while pressing the canister, holding the breath for 10 seconds.

  4. Wait 1-2 minutes for a second dose if prescribed.

Patient Education for MDIs

  • Teach patients to track their pulse rate, medication supply, and caution against overuse.

  • Advise rinsing the mouth, avoiding smoking, and cleaning inhaler equipment regularly.

NURSING CONSIDERATIONS

  • Assess for signs of dyspnea, abnormal breath sounds, and cough.

  • Monitor vital signs and hydration levels; reassess breath sounds after medication delivery.

  • Provide patient counseling around the use of rescue inhalers and identification for asthmatic patients.