Asthma and COPD Q 53

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A client with acute asthma showing inspiratory and expiratory wheezes and a decreased expiratory volume should be treated with which of the following classes of medication right away?

  

     A. Beta-adrenergic blockers

     B. Bronchodilators

     C. Inhaled steroids

     D. Oral steroids

    

    

Correct Answer: B. Bronchodilators

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Bronchodilators are the first line of treatment for asthma because bronchoconstriction is the cause of reduced airflow. Bronchodilators are indicated for individuals that have lower than optimal airflow through the lungs. The mainstay of treatment is beta-2 agonists that target the smooth muscles in the bronchioles of the lung. Various respiratory conditions may require bronchodilators, including asthma and chronic obstructive pulmonary disease.

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Option A: Beta-adrenergic blockers aren’t used to treat asthma and can cause bronchoconstriction. The catecholamines, epinephrine, and norepinephrine bind to B1 receptors and increase cardiac automaticity as well as conduction velocity. B1 receptors also induce renin release, and this leads to an increase in blood pressure. In contrast, binding to B2 receptors causes relaxation of the smooth muscles along with increased metabolic effects such as glycogenolysis.

Option C: Inhaled steroids may be given to reduce the inflammation but aren’t used for emergency relief. Inhaled corticosteroids have potent glucocorticoid activity and work directly at the cellular level by reversing capillary permeability and lysosomal stabilization to reduce inflammation. The onset of action is gradual and may take anywhere from several days to several weeks for maximal benefit with consistent use.

Option D: Corticosteroids produce their effect through multiple pathways. In general, they produce anti-inflammatory and immunosuppressive effects, protein and carbohydrate metabolic effects, water and electrolyte effects, central nervous system effects, and blood cell effects. Oral administration is more common for chronic treatment. Patients should receive non-systemic therapy whenever possible, to minimize systemic exposure.

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