Beta2-Adrenergic Agonists

Beta2-Adrenergic Agonists

Therapeutic Uses

• Relieve bronchospasms.

• Prevent exercise-induced bronchospasm (EIB).

• Medication selection depends on intended effect:

  • Fast relief (rescue inhalers)

  • Long-term management

• Beta-adrenergic agonists can be classified as:

  • Short-acting (SABAs)

  • Long-acting (LABAs)

Prototype and Other Medications

• Short-acting beta-adrenergic agonists (SABAs):

  • Prototype: Albuterol

  • Other SABA: Levalbuterol

• Long-acting beta-adrenergic agonists (LABAs):

  • Medications include:

    • Formoterol

    • Salmeterol

    • Terbutaline

    • Vilanterol

    • Olodaterol

Expected Pharmacologic Action

• Stimulate beta-adrenergic receptors of the sympathetic nervous system, resulting in:

  • Bronchodilation (relieves bronchospasm in lungs)

• Primary action: Open airways via sympathetic system stimulation.

• Minor roles include:

  • Increasing ciliary motility.

  • Depressing histamine release in lungs.

• Duration of action:

  • SABAs: 4-6 hours (important for asthma).

  • LABAs: Up to 12 hours (suitable for stable COPD).

Adverse Drug Reactions

• Possible side effects:

  • Tachycardia

  • Heart palpitations

  • Tremors

  • Angina (risk in compromised cardiac health)

• Rare adverse effects include:

  • Paradoxical bronchospasm (increased bronchoconstriction after treatment).

• Caution against overuse:

  • If using rescue inhalers more than twice a week, notify healthcare provider.

Nursing Interventions

• Monitor:

  • Tachycardia

  • Heart palpitations

  • Chest pain

• Report any of the above findings to the healthcare provider.

Administration

• Routes of administration:

  • Oral or inhalation

• Administration guidelines:

  • Short-acting for acute exacerbations.

  • Long-acting for long-term control.

  • Short-acting: Administer 30 minutes before exercise to prevent EIB.

• Combination with inhaled glucocorticoids:

  • Inhale beta-adrenergic agonist before glucocorticoid for better lung penetration.

• Forms of inhalation:

  • Pressurized metered dose inhaler (MDI)

  • Inhaled dry powder

  • Fine mist inhaler

  • Nebulizer

• Storage recommendations for MDIs:

  • Avoid extremes of temperature.

Safety Alerts

• Follow manufacturer’s instructions for inhalation devices to ensure proper delivery.

Client Instructions

• Advise clients to:

  • Avoid caffeine.

  • Notify provider if experiencing tremors affecting daily activities.

• Monitor for asthma exacerbation triggers:

  • Keep a log of exacerbation frequency and intensity.

  • Notify provider of any changes in pattern.

Contraindications and Precautions

• Avoid beta-adrenergic agonists in:

  • Clients allergic to the medication.

  • Clients with allergy history to beta-adrenergic agonists.

  • History of tachydysrhythmias or digitalis-induced tachycardia.

• Caution for clients with:

  • History of diabetes mellitus

  • Hyperthyroidism

  • Cardiovascular disease

  • Hypertension

  • Angina pectoris

• Close monitoring needed due to increased sympathetic stimulation.

Interactions

• Medication interactions:

  • Beta-adrenergic blockers: Reduce effectiveness of beta-adrenergic agonists.

  • Monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants: Increase risk of hypertension, tachycardia, and angina.

  • Hypoglycemic/antidiabetic medications: May require increased dosing due to hyperglycemic effects.