Antihistamines and Nasal Decongestants

 Allergic Rhinitis  Environmental allergens -> inflammation  Sinusitis  Middle ear infections  Upper Respiratory Infections  Common Cold  Virus or microbe damages tissue, -> inflammation 2

 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 3

(cont’d) ◦ Cough reflex  Irritant stimulates sensory receptors  Removes Respiratory secretions or foreign object 4

 Combined use of: ◦ Antihistamines, nasal decongestants, antitussives, and expectorants 5

 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 6

 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 7

(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 8

 Compete with histamine for receptor sites  Two histamine receptors ◦ H 1 (histamine 1) ◦ H 2 (histamine 2)  Antihistamines block H 1 receptors 9

 H ₂ stimulates gastric acid secretion, regulates gastrointestinal motility and intestinal secretion, increases GI secretions  Increases capillary permeability  The binding of H 1 and H 2 blockers to histamine receptors prevent histamine stimulation 10

 Respiratory antihistamines  Effects ◦ Antihistaminic ◦ Mild anticholinergic  Parasympathetic nervous system ◦ Sedative 11

 Antihistamines ◦ Cardiovascular: small blood vessels  Histamine effects ◦ Dilation ◦ Permeability  Antihistamine effects ◦ Prevent dilation ◦ Prevent increased permeability 12 (continues)

 Skin ◦ Prevent itching ◦ Wheal and flare  Anticholinergic ◦ Drying effect  Sedative ◦ Drowsiness 13

 Management of: ◦ Nasal allergies ◦ Seasonal or perennial allergic rhinitis ◦ Allergic reactions ◦ Motion sickness 14

 More effective in prevention  Give early ◦ Prevent binding of histamine receptors 15

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 16

 Older  Work both peripherally and centrally  Anticholinergic properties  Examples: diphenhydramine (Benadryl) and chlorpheniramine (Chlor- Trimeton) 17

 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 18

 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 19

 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 20

 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 21

 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 22

 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 23

 To reduce congestion  Two dosage forms ◦ Oral ◦ Topical  Nasal spray 24

 Prolonged effects  Less potent  No rebound congestion  Exclusively adrenergics  Example: pseudoephedrine (Sudafed) 25

 Adrenergics ◦ Prompt onset ◦ Sustained use ->rebound congestion: ischemia to local tissue which will respond with vasodilation  Both adrenergics and steroids ◦ Potent 26

 Anti-inflammatory ◦ Decrease inflammation ◦ Relieve nasal congestion 27

 Adrenergics ◦ I-desoxyephedrine (Vicks) ◦ Epinephrine HCl (Adrenalin Chloride) ◦ Oxymetazoline (Afrin) ◦ Phenylephrine (Neosynephrine) ◦ Pseudoephedrine HCl (Sudafed) ◦ Pseudoephedrine Sulfate (Afrin tablets) 28

 Intranasal steroids ◦ Beclomethasone dipropionate  Beconase  Vancenase ◦ Fluticasone Propionate  Flonase ◦ Mometasone Furoate Monohydrate  Nasonex 29

 Adrenergics ◦ Nervousness ◦ Insomnia ◦ Palpitations ◦ Tremors ◦ Increased blood pressure  Steroids ◦ Local mucosal dryness and irritation ◦ Decreased immune response ◦ Hyperglycemia 30

 Acute or chronic rhinitis  Common cold  Sinusitis  Hay fever  Other allergies 31

 Avoid decongestants in the following clients: ◦ Heart disease  Hypertensive disease ◦ Respiratory disease  Assess for drug allergies 32

 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 33

 Encourage use of flu vaccines  Encourage patients to talk with their pharmacist when on prescription drugs  Encourage adequate fluid intake 34

Expectorants and Antitussive Agents

 Aid in the expectoration (removal) of mucus  Reduce secretion viscosity  Stimulate flow of respiratory secretions 36

 By loosening and thinning sputum and bronchial secretions, the tendency to cough is indirectly diminished. ◦ These patients should get plenty of rest and fluids 37

 Relief of nonproductive coughs: ◦ Pertussis ◦ Common cold ◦ Bronchitis ◦ Laryngitis ◦ Sinusitis ◦ Influenza ◦ Pharyngitis 38

 Common side effects: ◦ Guaifenesin  Stimulates respiratory and gastric secretions  Nausea, vomiting  Gastric irritation ◦ Iodides  Increases respiratory secretions  May cause iodine poisoning 39

 Ipecac ◦ Low dose used as an expectorant ◦ Increases respiratory and gastric secretions  Terpin hydrate: Gastric upset 40

 Use with caution. ◦ Elderly  Encourage client to drink fluids.  Monitor for therapeutic effects.  Report a fever lasting longer than a week or extended cough 41

 Drugs used to control coughing ◦ Opioids and non-opioids ◦ Narcotics  Used for nonproductive coughs  Best used only if cough is painful or disrupts sleep 42

 Suppress the cough reflex by direct action on the cough center in the medulla ◦ Example: codeine + guiafenesin = Robitussin AC 43

 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 44

 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 45

 Benzonatate ◦ Dizziness, headache, sedation  Dextromethorphan ◦ Dizziness, drowsiness, nausea  Opioids ◦ Sedation, nausea, vomiting, lightheadedness, constipation, addiction, respiratory suppression 46

 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 47

 Report any of the following symptoms to the health care professional: ◦ Cough that lasts more than 2 weeks ◦ A persistent headache ◦ Fever ◦ Rash 48

 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 49

 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 50