1. Antihistamines and Nasal Decongestants
Chapter 14
Antihistamines and Nasal Decongestants

2. Allergic rhinitis p 364 Caused by environmental allergens
Immune response in nasal mucosa results in release of histamine which initiates the inflammatory response.

3. Inflammatory Response
Inflammation
Under the effects of histamine binding at the H1 receptor sites in the nasal mucosa and bronchi, small blood vessels are dilated and capillary walls have increased permeability.
The result is localized swelling and edema
This is an allergic reaction
Anaphylaxis

4. Common Cold p364 Virus infection Cough reflex Rhinovirus
Initiates the inflammatory response
Cough reflex
Irritant stimulates sensory receptors
Removes
Respiratory secretions
Foreign object

5. Symptomatic Treatment of common cold
Combined use of:
Antihistamines
Nasal decongestants
Antitussives
Expectorants

6. Antihistamines p365
Bind with H1 receptors sites in the tissues, thus blocking histamine from binding
Useful in treating allergic rhinitis

7. Antihistamines p365-366 Antihistamine effects Two classes
Prevent vasodilation
Prevent increased permeability
Two classes
Traditional (sedating)
Nondrowsy

8. Antihistamines Inflammation of the skin Stop or prevent prurutis
Wheal and flare
Inflammation of mucus membranes
Weak anticholinergic effects
Anticholinergic side effects
Dry mouth
Blurred vision
Constipation
Urinary retention
Cause sedation (newer antihistamines are non-drowsy

9. Antihistamines use Management of:
Seasonal or perennial allergic rhinitis
Allergic reactions
Motion sickness
Nausea
Coughs

10. Traditional Antihistamines p 368-370 Table 14-1 p368-370
Older drugs are sedating
Anticholinergic properties
Diphenhydramine (Benadryl): Prototype
Antihistaminic
Antiemetic
Anti-parkinson
Anti-tussive
Anti-pruretic

11. Traditional antihistamines cont table 14-1
Dimenhydrinate (Dramamine)
motion sickness
Meclizine (Antivert)
Promethazine (Phenergan)
antiemetic
sedative
Potentiates analgesics

12. Nonsedating Antihistamines Table 14-1 p368-370
Newer drugs
Longer duration of action
Increases compliance
Examples:
fexofenadine (Allegra)
loratadine (Claritin)
Cetirizine (Zyrtec)

13. Antihistamines: Nursing Implications p368
Assess allergy history
Encourage fluid intake of 3,000ml/day
Contraindications:
Uncontrolled glaucoma
Prostatic hypertrophy
Children less than 2 years old
Use with caution in patients with:
COPD
Cardiovascular disease
Asthma

14. Client Teaching Antihistamines Table 14-1 p 368
Instruction:
Avoid driving or activities that require alertness
No alcohol
No central nervous system depressants
Discontinue 4 days prior to allergy skin testing
May take with food or milk if GI upset

15. Decongestants p366 Constrict dilated blood vessels in the nasal mucosa
Useful in treating nasal congestion due to colds or flu type illnesses

16. Nasal Decongestants p366 Table 14-2 p 370
Therapeutic action: reduce nasal congestion
Two dosage forms: adrenergics
Oral
Topical spray

17. Treatment with Nasal Decongestants
Acute or chronic rhinitis
Common cold
Sinusitis

18. Nasal Decongestants Table 14-2, 14-3 p370-372
Adrenergics
Topical and oral route
Ephedrine (Vicks)
Naphazoline (Privine)
Oxymetazoline (Afrin)
Phenylephrine (Neosynephrine)
Pseudoephedrine (Sudafed)
Intranasal steroids
Topical route
Beclomethasone
Fluticasone (Flonase)
Mometasone (Nasonex)

19. Topical Adrenergic Decongestants Table 14-2 p3370-371
Nose sprays (topical administration)
Rapid onset of action
Prolonged use can lead to rebound congestion
Potent decongestant activity
Examples:
Epinephrine
Oxymetazoline
Phenylephrine
Teach: expectorate spray, don’t swallow

20. Oral Decongestants p367 Table 14-2 p370-371
Prolonged effects
Less potent than topical sprays
No rebound congestion
Exclusively adrenergics
Example:
Pseudoephedrine
Phenylephrine

21. Nasal Steroids p367 table 14-3 p372
Topical or local route
Anti-inflammatory action
Decrease inflammation
Relieve nasal congestion
Not immediate relief

22. Nasal Decongestants: Side Effects p370
Adrenergics side effects
Nervousness
Insomnia
Palpitations
Tremors
Increased BP and pulse
Intranasal steroid side effects
Local mucosal dryness and irritation

23. Nasal Decongestants: Nursing Implications p370
Contraindications
Heart disease
HTN
Hyperthyroidism
Administer nasal decongestants 20 minutes prior to meals for young children or debilitated pt.
Advise pt to check with physician before adding any new OTC medications

24. Administering nasal spray p374

25. Administering nose drops p375

26. Administering nasal inhaler p375

27. Combination products p 374, 378
Cold/allergy OTC products combine multiple drugs
Teach:
Read labels!!!!!
Consult pharmacist or physician before using OTC
Could be taking more of a prescribed drug
Interactions
Contraindications with disease states