1 / 19

CHAPTER 32

CHAPTER 32. Bronchodilator Drugs and the Treatment of Asthma. Common Diseases Affecting the Respiratory Tract. Chronic bronchitis – condition caused by chronic respiratory irritation, inflammation, and characterized by increased secretions and infection (COPD) smoking

riley-preston
Télécharger la présentation

CHAPTER 32

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER 32 Bronchodilator Drugs and the Treatment of Asthma

  2. Common Diseases Affecting the Respiratory Tract • Chronic bronchitis – condition caused by chronic respiratory irritation, inflammation, and characterized by increased secretions and infection (COPD) smoking • Emphysema – disease characterized by destruction of alveoli, labored respiratory gas exchange, and shortness of breath (↓exhale) • Asthma – inflammatory disease of the respiratory passageways characterized by bronchoconstriction and shortness of breath

  3. Emphysema • Destruction of alveolar walls – dose dependently related to smoking • Limits exercise tolerance – requires supplemental O2

  4. Asthma • 5% of US population – 5000 deaths / y • Bronchoconstriction – reversible smooth muscle contraction – controlled by • Contraction - parasympathetic – AC • Dilation – sym – β2 adrenergic receptor • Inflammation of bronchiolar mucosa • Shortness of breath, cough, wheezing, smothering feeling,  mucous secretion

  5. COPD • Affects 20% of Us pop. • Secondary to smoking “mucous escalator” • Combination of chronic bronchitis and emphysema irreversible, progressive does respond to treatment

  6. Inflammatory Mediators of the Respiratory Tract • Histamine • Eosinophilic chemotactic factor of anaphylaxis (ECF-A) • Prostaglandins and leukotrienes • Slow-reacting substance of anaphylaxis (SRS-A)

  7. Autonomic Control of the Respiratory Tract • Bronchiolar smooth muscle is relaxed by beta-2 adrenergic receptor stimulation • Bronchiolar smooth muscle is contracted by cholinergic receptor stimulation • Respiratory secretions are increased by cholinergic stimulation • Drugs that increase intracellular levels of cyclic AMP produce bronchodilation

  8. Bronchodilator Drugs • Sympathomimetics – drugs that stimulate beta-2 adrenergic receptors • Xanthine derivatives – theophylline • Parasympatholytics – drugs that block cholinergic receptors (anticholinergic drugs)

  9. Bronchodilators • Short acting – “rescue inhalers” 4-6 hr • Terbutaline (Brethine) • Albuterol (Proventil) • Long acting – 12 hr • Salmeterol (Severent) • Drugs of choice for mild asthma

  10. Beta Adrenergic Drugs • Epinephrine and isoproterenol are nonselective beta-1 and beta-2 agonists • Albuterol, terbutaline, and salmeterol are selective beta-2 agonists that do not cause excessive cardiac stimulation • Selective beta-2 drugs are preferred for the control of asthma • Epinephrine SC is the drug of choice to treat an acute attack of asthma

  11. Theophylline • Increases cyclic AMP levels to cause bronchodilation and inhibition of chemical mediator release from mast cells • Theophylline is usually administered orally • In COPD theophylline decreases secretions and stimulates respiration • Overdosage produces cardiac and CNS stimulation, and may cause seizures

  12. Corticosteroids • Drugs of choice for moderate – severe asthma • Anti-inflammatory – decrease airway lymphocytes & eosinophills - no effect on muscle spasm • Mucosal edema • Leukotriene secretion • Mucous secretion

  13. Corticosteroids • Given by aerosol BID-QID • Must use a “spacer” – prevents thrush • Beclomethasone (Vanceril) • Budesonide (Pulmocourt)

  14. Corticosteroids • Adrenal gland hormone derivatives used in inflammatory and allergic conditions • Administered orally or parenterally in acute asthmatic and inflammatory diseases • Administered by oral inhalation for the chronic control of asthma and related inflammatory conditions • Inhalation limits systemic toxicity

  15. Anticholinergic Drugs • Ipratropium bromide (Atrovent) is the only drug currently available • By blocking cholinergic receptors ipratropium produces bronchodilation and decreased respiratory secretions • The drug is administered by oral inhalation

  16. Leukotrienes Inhibitors • Anti-inflammatory drugs that interfere with the inflammatory actions of the leukotrienes • Zafirlukast (Accolate) and montelukast (Singulair) block leukotriene receptors • Zileuton (Zyflo) blocks the enzyme required for the formation of leukotrienes • Drugs are indicated for the chronic treatment and control of asthma

  17. Ant allergic Drugs • Cromolyn and nedocromil (Tilade) inhibit the antigen-antibody reaction on mast cells that triggers allergic reactions • Administration is by oral inhalation • Drugs are used on a daily basis and are intended to prevent or decrease allergic reactions • Several weeks are usually required for the full therapeutic effect

  18. Mucolytics • Mucolytics are intended to break apart and liquefy thick respiratory secretions to facilitate easier removal • Acetylcysteine (Mucomist) is the most widely used mucolytic and is inhaled by nebulization • Administration is usually followed by postural drainage and tracheal suction

More Related