1. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Chapter 22 Respiratory and Gastrointestinal Drugs

2. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Sympathomimetic Agents  Noninfectious respiratory diseases are divided into two groups.  Asthma is characterized by reversible airway obstruction.  Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airway obstruction. COPD is further divided into emphysema and chronic bronchitis. COPD is further divided into emphysema and chronic bronchitis. 2

3. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Sympathomimetic Agents  Beta-Adrenergic Agonists  Nonselective adrenergic agonist drugs stimulate beta receptors in the lungs and heart and alpha receptors in the heart.  Epinephrine and isoproterenol are nonselective adrenergic agonists.  Today, short- and long-acting β 2 -agonists are used to treat asthma and COPD.  Β 2 -Agonists stimulate receptors in the lungs.  Stimulation of these receptors produces bronchodilation.  Adverse effects include nervousness, tachycardia, and insomnia. 3

4. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Respiratory Drugs  Beta-Adrenergic Agonists  Short-Acting β 2 -Agonists These drugs are used to treat acute asthma attacks. These drugs are used to treat acute asthma attacks. They are usually administered via metered dose inhalers. They are usually administered via metered dose inhalers. They are available in tablet and liquid dose forms. They are available in tablet and liquid dose forms. Short-acting β 2- agonists are often used as prophylaxis prior to exercise or another known precipitating event. Short-acting β 2- agonists are often used as prophylaxis prior to exercise or another known precipitating event. 4

5. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Long-Acting β 2 -Agonists  These agonists have a delayed onset of action and a longer duration of action.  Onset of action is within 10-20 minutes and the duration of action of 12 hours.  These drugs are used as maintenance therapy in the treatment of asthma and COPD. 5

6. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Metered Dose Inhalers (MDI)  These devices deliver the medication directly to the bronchioles.  The total dose is kept low and side effects should be minimal.  The inhaled dose can be accurately measured.  Onset of action is rapid and predictable.  They are compact, portable, and sterile.  They can be difficult to use.  Spacers are available which makes the inhaler easier to use.  Adverse effects with MDI use include dry mouth. 6

7. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Corticosteroids  Steroids reduce the inflammation associated with airway obstruction.  They also inhibit the release of inflammatory substances.  Steroids are available as MDIs and oral and liquid dose forms.  The MDI has become the most common dose form used in treating asthma and COPD. 7

8. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Corticosteroids  Corticosteroids significantly improve pulmonary function with a decrease in wheezing, tightness, and cough.  These drugs are not used for acute attacks.  Chronic oral prednisone use is reserved for patients with severe asthma.  Adverse effects are dependent upon dose form, frequency of intake, total dose, and any preexisting conditions. 8

9. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Corticosteroids  Prolonged systemic use can lead to adrenal suppression, poor wound healing, and immunosuppression.  MDI use can lead to oral candidiasis.  Patients using inhaled steroids should be instructed to brush, floss, rinse, and spit, after each use. 9

10. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Leukotriene-Pathway Inhibitors  These drugs work by either preventing the synthesis of leukotrienes or by blocking leukotriene receptors.  Leukotriene release produces bronchoconstriction, increased mucus secretion, mucosal edema, and increased bronchial hyperreactivity.  These drugs are used to treat asthma and allergic rhinitis.  Adverse reactions include irritation of the stomach mucosa, headache, and altered liver function tests. 10

11. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Cromolyn  Cromolyn inhibits mast cell degranulation.  It is used for the prophylaxis of asthma.  It can be used in patients with chronic asthma or taken before exercise-induced asthma.  Adverse effects include cough, dry mouth, nausea, and headache.  It is available as a nebulizer or in a spinhaler dose form. 11

12. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Methylxanthines  Theophylline is the main drug in this category.  It is a bronchodilator with a narrow therapeutic window.  It is used to treat severe asthma and the bronchospasm associated with COPD.  Side effects include CNS stimulation, cardiac stimulation, and GI upset. 12

13. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Anticholinergic Drugs  Ipratropium bromide is an inhaled anticholinergic drug that is used to treat asthma and COPD.  Its anticholinergic effects produce a bronchodilating effect in the lungs.  Side effects include dry mouth. The patient should rinse after each inhaler use to minimize dry mouth. 13

14. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Nasal Decongestants  Nasal decongestants are α-agonists that act by constricting the blood vessels of the nasal mucous membranes.  Chronic use of topical decongestants can lead to rebound swelling and congestion.  Adverse effects include insomnia, excitation, and tachycardia. 14

15. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Expectorants and Mucolytics  Expectorants promote the removal of exudate or mucous from the respiratory passages.  Mucolytics destroy or dissolve mucus. 15

16. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Antitussives  These agents are used for the symptomatic relief of nonproductive cough.  Opioids and dextromethorphan are the most common antitussives. 16

17. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Dental Implications of the Respiratory Drugs 17

18. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Gastrointestinal Diseases  Gastrointestinal reflux disease (GERD) is a dental concern in and of itself.  Patients with GERD may not be able to remain in a supine position in the dental chair. A supine position may stimulate acid reflux.  The chair should be raised until the patient is comfortable. In some instances, the chair may need to be in a fully seated position.  Ulcers affect the stomach and small intestine.  Patients with either ulcers or GERD should avoid aspirin and NSAIDs to treat dental pain.  These drugs are irritating to the stomach and can cause ulcers and exacerbate symptoms of GERD. 18

19. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Gastrointestinal Drugs  Classes of drugs used to treat GERD and peptic ulcer disease are many.  They include histamine 2 -receptor blockers, proton pump inhibitors, and antacids. H 2 -blockers block gastric acid secretion by blocking the H 2 -receptors of the parietal cells.  Proton pump inhibitors are potent inhibitors of gastric acid secretion.  Antacids neutralize stomach acid production. 19

20. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Gastrointestinal Drugs  Most patients self-treat with antacids or over-the- counter H 2 -blockers or omeprazole.  Patients should be questioned about their use of these drugs during dental appointments.  Some oral adverse effects include mucosal atrophy of the tongue and dry mouth.  H 2 -blockers interact with ketoconazole, itraconazole, and benzodiazepines. 20

21. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Gastrointestinal Drugs  Ulcers may also be due to the bacteria H. pylori. Patients usually receive a combination of an antibiotic and either an H 2 -blocker or a proton pump inhibitor to treat this.  Misoprostol is a prostaglandin that is used to treat and prevent drug-induced ulcers.  Sucralfate is a complex of aluminum hydroxide and sulfated sucrose.  It is used to treat peptic ulcer disease. 21

22. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Gastrointestinal Drugs  Sucralfate binds with proteins and forms a complex that acts as a “bandage” on the ulcer site.  Adverse effects include constipation, dry mouth, nausea, rash, and dizziness.  Metoclopramide is a dopamine antagonist that stimulates the motility of the upper GI tract. It leads to an accelerated gastric emptying time. 22

23. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Gastrointestinal Drugs  Adverse effects include restlessness, drowsiness, fatigue, and extrapyramidal side effects.  Simethicone is combined with antacids and is used to relieve flatulence.  Simethicone lowers surface tension and breaks up gas pockets. 23

24. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Laxatives  Laxatives are used for a variety of reasons to include the treatment of constipation and bowel cleansing prior to certain procedures.  Bulk laxatives are considered more natural and increase peristalsis and facilitate movement through the intestine.  Lubricants can interfere with the absorption of fat-soluble vitamins and are no longer recommended. 24

25. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Laxatives  Stimulant laxatives act by producing local irritation to the intestinal mucosa.  Stool softeners accumulate water in the intestine and soften the stool so that it is easily expelled from the body.  Osmotic or saline laxatives produce their effect by osmotically holding water. 25

26. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Antidiarrheals  Drugs used to treat diarrhea are either adsorbents or opioid-like in action.  They are used to minimize fluid and electrolyte imbalances. 26

27. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Emetics  These drugs are used to treat people who have ingested or overdosed drugs that can be harmful. 27

28. Mosby items and derived items © 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Antiemetics  Vomiting can occur for any number of reasons to include the flu, motion sickness, pregnancy, drugs, infections, or chemotherapy.  Phenothiazines are used to control severe nausea.  Anticholinergic and antihistamine drugs are used for nausea and vomiting due to motion sickness.  Other antiemetics include trimethobenzamide, metoclopramide, benzquinamide, and cannaboids which are used for cancer chemotherapy patients.  All of these drugs cause sedation, dizziness, and dry mouth. 28