Drugs acting on the upper respiratory tract: antihistamines, decongestants, antitussives, and expectorants Flashcards
Histamine
Major inflammatory mediator in many allergic disorders
Antihistamines
Drugs that compete with histamine for specific receptor sites
H1 antagonists you need to know
Chlorpheniramine, fexofendaine (allegra), loratadine (Claritin), cetirizine (zyrtec), diphenhydramine (Benadryl)
Properties of antihistamines
Antihistaminic, anticholinergic, sedative
Antihistamine effects
Reduces dilation of blood vessels and reduces increased permeability of blood vessels; reduces salivary, gastric, lacrimal, and bronchial secretions, bind to histamine receptors thus preventing histamine from causing a response, drowsiness, anticholinergic effects,
Antihistamine indications
Management of nasal allergies, season or perennial allergic rhinitis, allergic reactions, motion sickness, Parkinson’s disease, sleep disorders. Could also be used to relieve symptoms associated with the common cold- sneezing, runny nose, palliative treatment- not curative
Antihistamine contraindications
KDA, Narrow angle glaucoma, cardiac disease, hypertension, kidney disease, bronchial asthma, COPD, peptic ulcer disease, seizure disorders, BPH, pregnancy
Antihistamines adverse effects
Anticholinergic effects: dry mouth, difficulty urinating, constipation, changes in visions. Drowsiness
What are the 2 types of histamine
Traditions and non sedating
Tradition antihistamine drugs
Brompheniramine, chlorpheniramine, diiphenhydramine, meclizine, promethasine
Nonsedating antihistamine drugs
Ioratadine, cetirizine, and fexofenadine
Nonsedating antihistamines characteristics and examples
Developed to eliminate unwanted adverse effects, mainly sedation, works peripherally to block the actions of histamine; thus fewer CNS adverse effects, longer duration of action which can increase compliance
EX: fexofenadine (allegra), loratadine (Claritin), Cetrizine (zyrtec)
Traditional antihistamines characteristics and examples
Older, work both peripherally and centrally, have anticholinergic effects, making them more effective than non sedating drugs in some cases
EX: diphenhydramine, bropheniramine, chlorpheniramine, meclizine, promethazine.
Nursing implications for antihistamines
- Gather data about condition or allergic reactions that required treatment- assess for drug allergies,
- contraindicated in the presence of acute asthma attacks and lower respiratory diseases, such as pneumonia. – Instruct patients to report excessive sedation, confusion, or hypotension,
- instruct patients to avoid driving or operating heavy machinery,
- advise against consuming alcohol or other CNS depressants,
- instruct patients not to take these medications with other prescribed or OTC medications without checking with their prescribers.
- Best tolerated when taken with meals (reduces GI upset),
- If dry mouth occurs, teach patients to perform frequent mouth care, chew gum, or suck on hard candy to ease discomfort,
- monitor for intended therapeutic effects.
Decongestants types
Adrenergic, corticosteroids