530 likes | 963 Views
Chapter 14. Antihistamines and Nasal Decongestants. Conditions Treated. Allergic Rhinitis Environmental allergens -> inflammation Sinusitis Middle ear infections Upper Respiratory Infections Common Cold Virus or microbe damages tissue , -> inflammation. Inflammatory Response.
E N D
Chapter 14 Antihistamines and Nasal Decongestants
Conditions Treated • Allergic Rhinitis • Environmental allergens -> inflammation • Sinusitis • Middle ear infections • Upper Respiratory Infections • Common Cold • Virus or microbe damages tissue, -> inflammation
Inflammatory Response • Release of several inflammatory and vasoactive substances (i.e. histamine) • Dilatation of arterioles in the nasal sinuses • Produces nasal congestion (increased secretions) • Edema, pruritis • Irritated pharyngeal mucosa -> coughing and pharyngitis
Inflammatory Response (cont’d) • Cough reflex • Irritant stimulates sensory receptors • Removes Respiratory secretions or foreign object
Symptomatic Treatment • Combined use of: • Antihistamines, nasal decongestants, antitussives, and expectorants
Allergic Rhinitis • immunological response to environmental allergens • Response: release of vasodilators: histamine and chemical agents • Results in an increase in mucus secretion, congestion and sneezing • Redness and tearing of the eye may result from allergens entering the eye
Histamine • Naturally occurring substance in the body • Release in response to invasion of microorganisms and allergens • Dilate arterioles to increase blood supply • Tissues become red and fluid accumulates
Histamine (cont’d) • Swelling occurs to prevent travel by microorganisms • Discomfort is due to this swelling • Leukocytes rush to the area • Itching is common with local contact of allergens
Antihistamines, Nasal Decongestants • Compete with histamine for receptor sites • Two histamine receptors • H1 (histamine 1) • H2 (histamine 2) • Antihistamines block H 1 receptors
Vasodilatation—GI effects • H₂ stimulates gastric acid secretion, regulates gastrointestinal motility and intestinal secretion, increases GI secretions • Increases capillary permeability • The binding of H1 and H2 blockers to histamine receptors prevent histamine stimulation
H1 Antagonists • Respiratory antihistamines • Effects • Antihistaminic • Mild anticholinergic • Parasympathetic nervous system • Sedative
Antihistamines • Antihistamines • Cardiovascular: small blood vessels • Histamine effects • Dilation • Permeability • Antihistamine effects • Prevent dilation • Prevent increased permeability (continues)
Antihistamines • Skin • Prevent itching • Wheal and flare • Anticholinergic • Drying effect • Sedative • Drowsiness
Antihistamines • Management of: • Nasal allergies • Seasonal or perennial allergic rhinitis • Allergic reactions • Motion sickness
Antihistamines • More effective in prevention • Give early • Prevent binding of histamine receptors
Classes of Antihistamines Two types: Traditional: sedating Diphenhydramine/Benadryl Meclizine/Antivert Promethazine/Phenergan Chlorpheniramine maleate/Chlor-Trimeton Newer drugs: less incidence of sedation Desloratadine/Clarinex Loratadine/Claritin, Alavert Fexofenadine/Allegra Cetirizine HCl/Zyrtec
Traditional Antihistamines • Older • Work both peripherally and centrally • Anticholinergic properties • Examples: diphenhydramine (Benadryl)and chlorpheniramine (Chlor-Trimeton)
Nonsedating/Peripherally Acting Antihistamines • Work peripherally • Eliminate sedation • Longer duration of action • Increases compliance • fexofenadine (Allegra), loratadine (Claritin) • Allegra replaced terfenadine/Seldane, which had serious cardiac side effects when combined with erythromycin and some antifungal agents
Current issues • Pseudoephederine is in many remedies • Can be extracted to make methamphetamines • Companies are removing or altering chemical structure • Legislation to regulate sale of items with pseudoephederine
Antihistamines: Nursing Implications • Assess allergy history • Contraindicated • Asthma attacks • Will not help acute attack • Chronic obstructive pulmonary disease • Drying of secretions may thicken the secretions • Cardiovascular disease • Inhibiting vasodilation may actually cause vasoconstriction
Client Teaching • Instruction for traditional/sedating antihistamines • May cause drowsiness • Avoid driving (also because of possible blurry vision) • No alcohol • No central nervous system depressants • May cause dry mouth and irritation to the pharynx • Use with caution if cardiovascular disease is present
Client Teaching • Non-Traditional Antihistamines • drowsiness • Avoid driving until effects of medication are known • Avoid alcohol and other CNS depressants when possible • Caution: hx cardiovascular, liver disease
Nasal Decongestants • Two main types are used: • Adrenergics (largest group) • Constrict dilated blood vessels in nasal mucosa -> reduce blood flow, edema • Corticosteroids • Reduce inflammation • May suppress normal immunological defense mechanisms
Goal of Nasal Decongestants • To reduce congestion • Two dosage forms • Oral • Topical • Nasal spray
Oral Decongestants • Prolonged effects • Less potent • No rebound congestion • Exclusively adrenergics • Example: pseudoephedrine (Sudafed)
Topical Decongestants • Adrenergics • Prompt onset • Sustained use ->rebound congestion: ischemia to local tissue which will respond with vasodilation • Both adrenergics and steroids • Potent
Nasal Steroids • Anti-inflammatory • Decrease inflammation • Relieve nasal congestion
Nasal Decongestants • Adrenergics • I-desoxyephedrine (Vicks) • Epinephrine HCl (Adrenalin Chloride) • Oxymetazoline (Afrin) • Phenylephrine (Neosynephrine) • Pseudoephedrine HCl (Sudafed) • Pseudoephedrine Sulfate (Afrin tablets)
Nasal Decongestants • Intranasal steroids • Beclomethasone dipropionate • Beconase • Vancenase • Fluticasone Propionate • Flonase • Mometasone Furoate Monohydrate • Nasonex
Nasal Decongestants: Side Effects • Adrenergics • Nervousness • Insomnia • Palpitations • Tremors • Increased blood pressure • Steroids • Local mucosal dryness and irritation • Decreased immune response • Hyperglycemia
Treatment with Nasal Decongestants • Acute or chronic rhinitis • Common cold • Sinusitis • Hay fever • Other allergies
Nasal Decongestants: Nursing Implications • Avoid decongestants in the following clients: • Heart disease • Hypertensive disease • Respiratory disease • Assess for drug allergies
Nursing considerations • Refer patients with acute respiratory infections, chronic illnesses, fever and prolonged symptoms to their provider • Patients with hypertension need regular monitoring while taking these meds • Educate: how to reduce the spread of infection
Nursing considerations • Encourage use of flu vaccines • Encourage patients to talk with their pharmacist when on prescription drugs • Encourage adequate fluid intake
Expectorants and Antitussive Agents • Aid in the expectoration (removal) of mucus • Reduce secretion viscosity • Stimulate flow of respiratory secretions
Secretions • By loosening and thinning sputum and bronchial secretions, the tendency to cough is indirectly diminished. • These patients should get plenty of rest and fluids
Cough Relief • Relief of nonproductive coughs: • Pertussis • Common cold • Bronchitis • Laryngitis • Sinusitis • Influenza • Pharyngitis
Expectorants: Side Effects • Common side effects: • Guaifenesin • Stimulates respiratory and gastric secretions • Nausea, vomiting • Gastric irritation • Iodides • Increases respiratory secretions • May cause iodine poisoning
Expectorants: Side Effects • Ipecac • Low dose used as an expectorant • Increases respiratory and gastric secretions • Terpin hydrate: Gastric upset
Expectorants: Nursing Implications • Use with caution. • Elderly • Encourage client to drink fluids. • Monitor for therapeutic effects. • Report a fever lasting longer than a week or extended cough
Antitussives • Drugs used to control coughing • Opioids and non-opioids • Narcotics • Used for nonproductivecoughs • Best used only if cough is painful or disrupts sleep
Opioid Antitussives • Suppress the cough reflex by direct action on the cough center in the medulla • Example: codeine + guiafenesin = Robitussin AC
Non-narcotic Antitussives • Dextromethorphan • Suppresses the cough reflex by direct action on the cough center in the medulla; a chemical derivative of the opiate narcotics • Result: diminished cough • Produces no respiratory depression, analgesia, or dependence • Example: Robitussin-DM
Non-narcotic Antitussives • Benzonatate • A derivative of procaine (local anesthetic action); impairs the sensation of the stretch receptors in the respiratory tract • No analgesic affect • No sedation/respiratory depression • Example • Tessalon
Antitussive Agents: Side Effects • Benzonatate • Dizziness, headache, sedation • Dextromethorphan • Dizziness, drowsiness, nausea • Opioids • Sedation, nausea, vomiting, lightheadedness, constipation, addiction, respiratory suppression
Antitussives: Nursing Interventions • respiratory assessment • Teaching: • Avoid driving, operating heavy equipment • Don’t drink liquids for 30 to 35 minutes after taking a cough syrup or using a cough lozenge
Antitussive Agents: Client Teaching • Report any of the following symptoms to the health care professional: • Cough that lasts more than 2 weeks • A persistent headache • Fever • Rash
Nursing Considerations • Assess: • cough and sputum (color, odor, amount and viscosity) • other drugs patient may be taking, possible drug interactions • Give syrups last when giving other medications • No fluids or food immediately after syrups
Nursing Considerations • Child safety • Humidifiers (clean regularly, do not add medications) • Control and avoid environmental irritants (smoke and pollution) • Teach infection prevention • Encourage fluids in general to help thin secretions