1. Allergy and Respiratory Medications
Chapter 11
Allergy and Respiratory Medications

2. Chapter 11
Lesson 11.1

3. Learning Objectives
Identify major antihistamines used to treat breathing problems
Describe the action of antitussive medications
List medications used to treat and prevent asthma attacks

4. Learning Objectives (cont.)
Describe the major actions and the adverse reactions of the two main categories of bronchodilators

5. Respiratory System Upper Respiratory System Lower Respiratory System
Oral and nasal cavity, sinuses, pharynx,
larynx, and trachea
Lower Respiratory System
Right and left bronchi, right and left lungs, bronchioles, and alveoli
The upper respiratory system is a passageway for air to move through as it travels into lower structures of the system. It also filters and humidifies air that is inhaled.
The function of the lower respiratory system is to exchange oxygen and carbon dioxide between the alveoli and the blood.
The respiratory system is a primary regulator of the acid-base (pH) balance in the body.
Diseases such as asthma, chronic bronchitis, emphysema, lung cancer, or infections such as the common cold or pneumonia will directly effect the functioning of the respiratory system.

6. Antihistamines Six Major Groups Action
Compete with histamine for H1 receptor sites to limit its effectiveness
Limits vasodilation, capillary permeability, and swelling
Limits acetylcholine release, which dries secretions in the bronchioles and gastrointestinal system
Sedative effect on the CNS
Histamine is released (by mast cells and basophils) when the body is injured.
Histamine dilates the capillaries of the smooth muscle and vascular system.
Antihistamines relieve the effects of histamine on body organs and structures.
The six major groups of antihistamines are found in Table These groups vary in characteristics and action.

7. Antihistamines (cont.)
Uses
Seasonal allergic rhinitis (SAR)
Perennial allergic rhinitis (PAR)
Perennial nonallergic rhinitis (PNAR)
Relieve symptoms of allergic disorders
Adjunctive therapy for anaphylaxis
Sedation
Allergic rhinitis is a condition in which a person has a reaction to outdoor allergens (SAR) or indoor allergens (PAR). Perennial nonallergic rhinitis (PNAR) is a condition in which inflammatory symptoms are caused by problems other than allergens.
Histamine plays a role in producing the inflammatory symptoms in these conditions: watery eyes, nasal stuffiness, postnasal drip, and sneezing.
Antihistamines are used for hives, angioneurotic edema, serum sickness, and blood-product reactions and are a common ingredient in cold remedies because they decrease mucous secretion and cause drowsiness at bedtime.

8. Antihistamines (cont.)
Adverse Reactions
Changes in blood pressure, blurred vision
Tachycardia, insomnia, dry mouth, nausea
Restlessness, excitability, sedation, tinnitus
Drug Interactions
Nursing Process
Some patients might experience CNS overstimulation and others CNS sedation from antihypertensives.
Antihistamine overdosage is potentially fatal, particularly in children, because the CNS is stimulated and depressed at the same time.
What drugs increase the effect of antihistamines? (CNS depressants such as hypnotics, sedatives, tranquilizers, depressant analgesics, alcohol)
Antihypertensives strengthen the action of other drugs such as anticholinergics and may mask ototoxicity from drug therapy. These medications also can interfere with the effect of anticholinesterase drugs and may decrease the effect of corticosteroids and hormones.

9. Antitussives Actions: Uses: Depress the cough center in the brain
Anesthetize stretch receptors in the respiratory tract
Soothe irritated areas in the throat
Uses:
Relief of overactive or nonproductive cough
Antitussives have central, peripheral, and local nervous system effects in the body.
Antitussives are commonly combined with other drugs and are usually sold as OTC drugs. Antitussives with codeine are typically sold as prescription drugs.
Antitussives with codeine depress the cough center in the brain. Antitussives without codeine act only peripherally and locally in the body.

10. Antitussives (cont.) Adverse Reactions Drug Interactions
Constipation, drowsiness, dry mouth, nausea, postural hypotension
Drug Interactions
Nursing Process
Antitussives have an additive effect with other CNS depressants and increase the analgesic effect of aspirin.
In reviewing the nursing process, what assessments should a nurse make before administering an antitussive with codeine? What nursing diagnoses could be made?
What planning should be done? Implementation? What should the nurse evaluate to verify medication effectiveness?

11. Asthma
Asthma is a condition that involves increased inflammation, swelling, and mucus production that lead to bronchiolar constriction. The person is able to breathe air into the lungs but has difficulty breathing out. Wheezing results because the person works to force air out through narrowed, mucus-filled passages during expiration.
The four classes of asthma severity include mild intermittent, mild persistent, moderate persistent, and severe persistent.
What factors may cause asthma? (enzyme deficiency, allergens, reflex response to cold, dry air, vigorous exercise)
Asthma may be genetic.
Asthma can be a chronic condition.
Preventive treatment is important.

12. COPD
COPD is a chronic, disabling disorder that causes destruction of alveolar walls. This destruction creates unequal areas of ventilation and perfusion in the body, and oxygen and carbon dioxide exchange is impaired. Patients experience difficulty in expiration.
COPD patients are seldom symptom-free, and medications are administered to dilate the bronchioles and help thin secretions.
Asthma and COPD are called obstructive airway diseases. You may outgrow asthma, but COPD is irreversible.
The medications used for these diseases will be discussed at the same time.

13. Asthma and COPD Medications
Prophylactic treatment
Cromolyn sodium
Nedocromil sodium
Actions:
Slows down destruction of sensitized mast cells; also may provide hyposensitization (decrease in allergic response)
Prophylactic treatment is essential in the prevention of asthmatic episodes.
Why are cromolyn sodium and nedocromil sodium only used in prevention of asthma attacks? (They have no antihistaminic, antiinflammatory, or bronchodilator activity.)
When mast cells are destroyed, they release histamine and the slow-reacting substance of anaphylaxis (SRS-A) that are created by breathing in specific antigens. By slowing the destruction of mast cells, the symptoms of asthma can be prevented.
What is a possible effect of long-term use of cromolyn? (Cromolyn provides hyposensitization after long-term use by preventing the release of phospholipase, an enzyme that assists in the release of chemical mediators from nonsensitized mast cells.)

14. Asthma and COPD Medications (cont.)
Bronchodilators
Sympathomimetics
Relax smooth muscle of bronchi (dilate)
Vasoconstriction of blood vessels in body (decreases mucosal and submucosal edema)
Increase the rate and force of heart contraction
Uses:
Relief of symptoms of bronchospasm in acute or chronic asthma, bronchitis, and COPD
Several types of bronchodilators may be used to open the bronchi and allow air to flow in and out of the lungs more freely.
Sympathomimetics are beta-adrenergic agents, which dilate the bronchi through their action on beta-adrenergic receptors.
An increase in rate and force of heart contraction is an undesired effect of sympathomimetic bronchodilators. Patient teaching is important to alleviate concern when this occurs.
What are the adverse reactions related to these drugs? Can taking two or more sympathomimetic drugs together increase the severity of adverse reactions?
Using the Nursing Process, what are the key points for assessment? Diagnosis? Planning? Implementation? Evaluation?

15. Asthma and COPD Medications (cont.)
Xanthines
Relax smooth muscle in the bronchi and blood vessels in the lungs
Directly act on the kidney to produce an increase in urine production
CNS effects
Uses
Adjunctive therapy for bronchospasm in acute and chronic bronchial asthma, bronchitis, emphysema
Treatment of neonatal apnea
Acute pulmonary edema
Xanthines also cause myocardial stimulation, increase the rate of breathing, have effects on metabolism, and release epinephrine from the adrenal medulla.
Xanthine derivatives are used in the treatment of acute pulmonary edema. They promote bronchodilation and diuresis.
What are some adverse reactions and drug interactions to be aware of with xanthine derivatives?
What are some other physiologic effects of this drug category?

16. Asthma and COPD Medications (cont.)
Leukotriene Receptor Inhibitors
Reduce symptoms of asthma by blocking receptors for cysteinyl leukotrienes C4, D4, and E4
Uses
Treat acute or chronic asthma in patients unable to take inhaled glucocorticoids
Leukotriene receptor inhibitors are the newest category of drugs used to treat asthma.
Cysteinyl leukotrienes (leukotrienes bound to the amino acid cysteine) cause bronchoconstriction, vascular permeability, and mucous secretion.
Should these drugs be taken before or after meals? (These drugs are rapidly absorbed and should be taken on an empty stomach, because food interferes with their absorption.)
Adverse reactions are minimal. Headache is the most common side effect. A few patients may experience infection, nausea, and diarrhea.
What drugs do leukotriene receptor inhibitors interact with? (warfarin, erythromycin, theophylline, aspirin)

17. Asthma and COPD Medications (cont.)
Corticosteroids
Block reaction to allergens and reduce airway hyperresponsiveness
Inhibit cytokine production, protein activation, and inflammatory cell migration and activation
Uses
Inhaled, long-term asthma control
Systemic; often used to get quick control of the disease when beginning long-term therapy or to speed recovery from severe episodes
Corticosteroids are the most powerful and consistently effective medications for long-term control of asthma. Side effects: Inhaled corticosteroids may cause cough, dysphonia (hoarseness), and oral thrush. Systemic corticosteroids in high doses can slow growth in children and cause osteoporosis in adults.
Adverse reactions when used for a short time include brief abnormalities in glucose metabolism, increased appetite, fluid retention, weight gain, mood alterations, hypertension, and peptic ulcers.
Inhaled corticosteroids do not interact with many drugs. Systemic corticosteroids have many interactions that are discussed later in the chapter.
Nursing Process: What nursing assessments would the LPN/LVN make before administering these drugs? What nursing diagnoses? What planning would occur? What interventions? What would you evaluate to verify effectiveness?

18. Chapter 11
Lesson 11.2

19. Learning Objectives
Identify at least six medications commonly used as decongestants
Describe the mechanism of action for expectorants
List the major contraindications to the use of nasal steroids

20. Decongestants Decongestants
Directly affect alpha receptors of blood vessels in the nasal mucosa, causing vasoconstriction
Uses: relieve nasal congestion from allergies and upper respiratory infections
Why should decongestants not be used for a prolonged period of time?
Why are these medications not used in patients on antihypertensive therapy or those taking cardiotonic drugs (digoxin)?
Why are pediatric decongestants no longer available as OTC medications?

21. Expectorants Expectorants
Decrease the thickness of respiratory secretions, which facilitate expectoration
Uses: treat productive cough, assist with thick mucus
Expectorants are commonly used in patients with COPD in whom mucus is thick and hard to expectorate.
GI upset is a common adverse reaction. Expectorants may increase bleeding tendencies in patients taking anticoagulants.
What patient teaching should be implemented if a patient is taking a decongestant? What if they are taking an expectorant?

22. Topical Intranasal Steroids
Action
Antiinflammatory, reduce nasal congestion
Uses
Treatment of allergic, mechanical, or chemically induced local nasal inflammation or nasal polyps when usual treatment has failed to work
Adverse reactions
Asthma, headache, light-headedness, loss of sense of smell, nasal irritation and dryness, nausea, nosebleeds, perforation of nasal septum, altered sense of taste and smell
Topical intranasal steroids vary in effectiveness in individuals. Generally, these are prescribed for patients only when more common treatments are ineffective.
Rebound congestion can occur with topical intranasal steroids. Steroids can also interact with many other drugs.
Do you think you’d take these drugs if you experienced the adverse reaction of loss of sense of smell?

23. Complementary and Alternative Therapies
Allergy
Grape seed, stinging nettle, coleus, vitamin C
Asthma
Cordyceps, Tylophora, grape seed, coleus, vitamin C
Cold
Arabinoxylane, echinacea, elderberry, astragalus, goldenseal, grapefruit seed extract, zinc, vitamin C
Cough
Ground ivy, thyme, licorice, marshmallow
What types of risks are associated with these therapies?
What are some reasons for the FDA not issuing approval for many complementary therapies?
Has anyone had any experience with complementary therapies? What types of information should the LPN/LVN provide to clients using any of these therapies?
Tyler’s Honest Herbal is considered to be one of the reputable references for herbal information.