Anthistamines, Decongestants, Antitussives, and Expectorants Flashcards
(30 cards)
Common Cold
Most caused by viral infection
Excessive mucus production results from inflammatory response to the invasion
Treatment is SYMPTOMATIC only, not curative
Antihistamine Mechanism of Action
Drugs that compete with histamine for specific receptor sites: H1 and H2
Block action of histamines at receptor sites
Cannot push a histamine off the receptor if it is already bound
SHOULD BE GIVEN EARLY IN TREATMENT
Properties of Antihistamines
Antihistaminic
Anticholinergic
Sedative
Indications for Antihistamines
Seasonal or perennial allergic rhinitis Anaphylaxis Angioedema Drug fevers Insect bite reactions Urticaria Nasal allergies Motion sickness Parkinson's disease Sleep disorders
Contraindications of Antihistamines
Narrow-angle glaucoma Cardiac disease, HTN Kidney disease COPD, bronchial asthma Sole drug therapy during acute asthma attacks Peptic ulcer disease Seizure disorders Benign prostatic hyperplasia Pregnancy (cautiously, need to know category)
Adverse Effects of Antihistamines
Anticholinergic (drying) effects are most common: dry mouth, difficulty urinating, constipation, changes in vision
Drowsiness
Type of Traditional Antihistamine
Diphenhydramine (Benadryl)
Sedating
Types of Nonsedating Antihistamines
Loratadine (Claritin)
Cetirizine (Zyrtec)
Fexofenadine (Allegra)
Nonsedating/Peripherally Acting Antihistamines
Work peripherally to block the actions of histamine; thus, fewer CNS adverse effects
Longer duration of action (increases compliance)
Traditional Antihistamines
Older
Work peripherally and centrally
Have anticholinergic effects, making them more effective than nonsedating drugs in some cases
Nursing Implications for Antihistamines
Use caution with patients with increased intraocular pressure, cardiac or renal disease, hypertension, asthma, COPD, peptic ulcer disease, BPH, or pregnancy
Instruct patients to report excessive sedation, confusion, or hypotension
Instruct patients not to take OTC medications with these medications without checking with their prescribers
Best tolerated when taken with meals
Nasal Congestion Properties
Excessive nasal secretions
Inflamed and swollen nasal mucosa
Primary causes include allergies and upper respiratory infections
Types of Decongestants
Adrenergics (largest group)
Anticholinergics (less commonly used)
Corticosteroids
Two dosage forms: oral or inhaled/topically applied
Oral Decongestants
Prolonged decongestant effects but delayed onset
NO REBOUND CONGESTION
Exclusively adrenergics
Pseudoephedrine (Sudafed)
Topical Nasal Decongestants
Prompt onset, potent
Sustained use over several days causes rebound congestion, making the condition worse
Phenylephrine
Intranasal Steroids
Beclomethasone dipropionate (Beconase)
Fluticasone (Flonase)
Triamcinolone (Nasocort)
Mechanism of Action for Nasal Decongestants
Site of action: blood vessels and surrounding nasal sinuses
Adrenergics: constrict small blood vessels that supply upper respiratory tract structures to shrink tissues and allow for better drainage
Nasal steroids: antiinflammatory effect, work to turn off the immune system cells involved in the inflammatory response
Indications for Nasal Decongestants
Relief of nasal congestion associated with acute/chronic rhinitis, common cold, sinusitis, hay fever, allergies
May be used after nasal surgeries
Contraindications of Nasal Decongestants
Narrow-angle glaucoma, uncontrolled cardiovascular disease, hypertension, diabetes and hyperthyroidism, inability to close the eyes, history of CVA or TIA, long-standing asthma, BPH, diabetes
Nursing Implications for Nasal Decongestants
Patients should avoid caffeine
Patients should report fever, cough, or other symptoms lasting longer than 1 week
Antitussives
Drugs used to stop or reduce coughing
Opioid and nonopioid
USED ONLY FOR NONPRODUCTIVE COUGHS
May be used in cases where coughing is harmful
Mechanism of Action for Antitussive Opioids
Suppress the cough reflex by direct action on the cough center in the medulla
Analgesia, drying effect on the mucosa of the respiratory tract, increased viscosity of respiratory secretions, reduction of runny nose and postnasal drip
CODEINE
Mechanism of Action for Antitussive Nonopioids
DEXTROMETHOPHAN works in the same way as opioids
No analgesic properties
No CNS depression
BENZONATATE (TESSALON): suppresses the cough by numbing the stretch receptors in the respiratory tract and prevent reflex stimulation of the medullary cough center
Contraindications for Antitussives
Opioid dependency
Respiratory depression
