1. Chapter 14 Antihistamines, Nasal Decongestants, Expectorants, and Antitussives

2. Introduction
Antihistamines and nasal decongestants are used to treat the common cold and allergic rhinitis
Nasal decongestants may also be used to treat sinusitis, middle ear infections, and upper respiratory tract infections
Symptoms of the common cold and allergic rhinitis are similar, however their pathophysiology is quite different S

3. Common Cold Caused by a viral infection
Virus invades the respiratory tract
Injures local cells
Initiates inflammatory response in the affected area
Leads to:
Increase in blood flow to area
Local edema
Nasal discharge
May lead to secondary bacterial infection and nasal congestion S

4. Allergic Rhinitis
Condition of an allergy-prone individual cause by an immunological response from the contact of one or more environmental allergens with the mucosal tissue
Inflammatory response causes release of histamines and other chemical agents
Leads to:
Increased secretion of mucus, congestion, and sneezing
Redness and tear may result as a result of allergen particles entering the eye S

5. Antihistamines Role of Histamine in the Body
Released in the body as a response to tissue damage and the presence of microorganisms and allergens invading body tissue
Dilates arterioles
Allows for increased blood supply to capillaries
Leads to arterioles becoming red and large amounts of fluids leak into the interstitial tisssues
Inflammatory response allows for leukocytes to enter the area S

6. Antihistamines(cont.)
Do not affect the release of histamines
Action: block the action of histamine at the H1 histamine receptor sites
Most useful in the treatment of rhinitis
Some may exert a local anesthetic action
Effective in preventing or countering motion sickness, nausea, or vomiting
May exert multiple effects:
CNS Depressant activity
Anticholinergic activity
Varying degrees of sedation when combines with other depressant drugs or alcohol beverages S

7. Caution with Antihistamines
Anticholinergics
Respiratory Disorders
Nursing mothers
Older Adults (Over 60 years of age and older) S

8. Antihistamine Drugs Promethazine
Contraindicated in comatose clients and other state of CNS depression
Avoid with clients with hepatic disorders and those sensitive to phenothiazine drug
Desloratadine (Clarinex)
Nonsedating antihistamine, relief of nasal and other symptoms related to seasonal allergies, adverse effects: dry mouth and pharyngitis
Fexofenadine (Allegra)
When combined with pseudoephedrine (Allegra-D), not recommended for person with hypertension, diabetes, ischemic heart disease, glaucoma, hyperthyroidism, renal impairment, or prostate cancer
Cetirizine
Active metabolite of hydroxyzine, does not cause drowsiness
Levocetirizine dihydrochloride (Xyzal)
Oral antihistamine for allergic rhinitis and urticaria
Approved for adults and children 6 years and older
Excreted in urine and should be cautiously use in clients with renal impartment
Contraindicated in adults with end-stage renal disease (ESRD) and children 6-12 with renal impairment
Olopatadine hydrochloride (Patanase), azelastine (Astepro)
Should not consume with other OTC antihistamines or alcohol while using these agents

9. Antihistamine Drugs Commonly used for symptoms of Allergies
Block peripheral H1 histamine receptors than those in the CNS
Results in lower incidence of sedation S

10. Nursing implications for Antihistamines
Encourage the client to read the directions for use and warnings on OTC products and to follow instructions
Clients with hypertension should have their blood pressure monitored with the adverse effect of further increasing blood pressure
Antihistamine agents can cause increased intraocular pressure worsening glaucoma
Can cause urinary retention worsening prostatic hypertrophy
Emergency supplies should be on hand for nurse
Ex: epinephrine, Benadryl, corticosteroids
Referral to health care provider for possible desensitization
Try to determine offending allergen, suggest ways to minimize contact S

11. Question
Name four instances in which you should caution using antihistamines? S

12. Expectorants pg 464 Aid in the expectoration of mucus
Reduces the viscosity of secretions
Stimulates the flow of respiratory secretions Q

13. Secretions
Thinning and loosening of endobronchial mucus and phlegm to be expelled by cough
Teach to cough productively by sitting in upright position & taking slow, deep breaths first
Encourage fluids to help liquefy secretions
Increased secretion activity in the respiratory tract aids in hydrating dry, irritated tissue Q

14. Expectorants
Iodides-potassium iodide (saturated solution of potassium iodide)-used because of their ability to increase secretions of respiratory tract fluids
Metallic taste, fever, anorexia and limited use because of possible hypersensitvity Q

15. Decongestantspg 452
Nasal Decongestants constrict dilated blood vessels in the nasal mucosa by stimulating alpha-adrenergic nerve receptors in vascular smooth muscle
Reduces flow of blood in edematous area
Slows the formation of mucous; permits better drainage
Most common medication forms of decongestants
Nasal inhalation
Oral A

16. Common Problemspg452
Rebound congestion, return of excessive tissue fluid occurring as a result of use for an extended time and dosing beyond recommendation by manufacturer Excessive use causes local Ischemia along with Irritation of the Nasal mucosa; that leads to extensive secondary vasodilation and congestion Adverse effects such as elevation of blood pressure and CNS stimulation, may occur if decongestant solutions drains through nasal passage and swallowed by the client A

17. Nasal inhalantspg
(ex. Afrin, Duration, Adrenalin Chloride) Inhalers are generally plastic containers containing an inert fibrous material impregnated with a volatile decongestant drug Container is open, inhaled through nostrils, vapor decongestant drug comes in contact with nasal mucosa and produces decongestant action A

18. Oral decongestantspg458
(ex. Drixoral tablets, Sudafed)pg 460 Generally longer duration of action than that of the topical agents, BUT effect tends to be less constrictive May affect vascular beds other than those found in the nasal mucosa May precipitate or aggravate High BP, cardias arrhythmias, ishemic HD, DM and hyperthyroidism A

19. Palliative Carepg458
For the common cold and allergic rhinitis decongestants and antihistamines are NOT curative Cromolyn Sodium has proved to be effective in prevention/treatment of allergic rhinitis, it inhibits histamine release and the release of other chemical agents freed as a result of an allergic response by stabilizing mast cells; therefore reduce the severity/ frequency of acute episodes of allergic rhinitis A

20. Nursing Implicationspg470
Teach clients the proper way to administer nasal sprays and nose drops
Topical nasal decongestants should be given 20 mins before meals, so the nasal passages will be clear for breathing during eating or sucking
Hypertensive clients should monitor BP, when taking Antihistamines/Decongestants with adverse effect increasing BP
Children under 6 Do not take epinephrine HCl A

21. What is the cause of rebound congestion?
Question
What is the cause of rebound congestion? A

22. Intranasal Steroidspg458
(ex. Beclomethasone dipropionate (Beconase), mometasone (Nasonex), fluticanose propionate (Flonase)
Local corticosteroids used in conjunction with antihistamines and decongestants to address congestion and associated with allergies
Applied nasally, but rather than a spray, administered as vapors
Intranasal steroids also are used adjunct therapy for clients with asthma
Unlike, nasal decongestants, I.S. administration does not produce immediate effects, regular use is required, for full therapeutic benefits from these products K

23. Intranasal Steroids (cont.)pg458,464
Ciclesonide, 7th newest nasal corticosteroid, indicated in the treatment of nasal symptoms of seasonal rhinitis in adults and children 6 years of age and older and nasal symptoms of perennial allergic rhinitis in adults and children 12 years of age and older
When symptoms of seasonal or perennial rhinitis do not respond well to conventional forms of therapy, intranasal corticosteroid administration may be advisable
Use of saline nose drops has proved to be successful for those clients taking other decongestants and those just using the saline drop for nasal congestion; advantage is it is not habit- forming, can be used more often and are less expensive K

24. Expectorants
Iodides-potassium iodide (saturated solution of potassium iodide)-used because of their ability to increase secretions of respiratory tract fluids
Metallic taste, fever, anorexia and limited use because of possible hypersensitvity Q

25. Antitussives Agent that prevents or relieves coughs Coughs
Physiological mechanism useful in removing foreign material and excessive secretions from the respiratory tract
May be productive OR nonproductive
Involuntary coughs should not be suppressed unless they cause respiratory discomfort or does not facilitate removal of excess secretions from the respiratory tract S

26. Major Drawbacks of Antitussives
May cause independence, bronchial constriction, CNS depression, and constipation
Use Cautiously In Clients with:
Preexisting Pulmonary distress
Older Adults
Children
Clients using most Psychotropic Agents
Clients using Sedative Hypnotics
Clients using Alcohol
Clients using other CNS Depressants S

27. Antitussive Drugs Codeine and hydrocodone
Considered to be the most effective and reasonably safe
Direct depressant effect on the medulla of the brain depressing the cough reflex
Ex: guaifenesin and codeine (Robitussin A-C)
Expectorant combined with Antitussive
Used for temporary relief of cough due to throat irritation
Irritation can lead to a more serious condition
Ex: bronchitis S

28. Antitussive Drugs dextromethorphan HBr
Chemical derivative of the opiate antitussives
Direct depressant effect on the medulla of the brain depressing the cough reflex
Does NOT cause CNS depression, analgesia, or dependence
Dextromehorphan is used in most nonprescription cough syrups
Intended for Adults and Children over 4 years old
Ex: Robitussin DM and Benylin DM S

29. Antitussive Drugs Benxonatate (Tessalon) Derivative of procaine
Acts peripherally by providing local anesthetic action, impairs sensation of the stretch receptors located in the respiratory tract, lungs, and pleura, thereby interfering with the cough reflex
Does NOT impair respiration or have an analgesic effect
Acts within minutes with duration of effects lasting 3-8 hours S

30. Antitussive Drugs Diphenhydramine HCl (Benadryl) Potent antihistamine
Anticholinergic properties
Must be used with caution in clients with:
Glaucoma
Prostatic hypertrophy
Obstructive pulmonary diseases
When used with alcohol or other CNS depressants, excessive sedation may occur
Client should be made aware of possible impairment of physical or mental capabilities, or both while taking the drug S

31. Nursing Implications
Antitussives are commonly used in the form of syrups
Monitor for therapeutic and untoward effects, sensitivity to any drugs, and drug interactions
Administering Antitussives:
Syrup should be give last when its purpose is for a soothing effect
Should NOT be immediately followed by water or other liquids or foods
Must be kept out of reach of children, may be potential for accidental poisoning due to the pleasant flavoring
Promote comfort in persons with chronic coughs
Environmental irritants should be controlled or avoided as much as possible
Assure high fluid intake 2,000-2,500 mL/day to keep secretions liquid
Assess for overhydration (most common in adults and small children) S

32. Question
A client receiving an antitussive with hydrocodone should be monitored for:
Constipation
Cholinergic effects
Diarrhea
Urinary frequency