objective 2.3 (1) Flashcards
what is the treatment of the common cold?
Involves combined use of antihistamines, nasal decongestants,
antitussives, and expectorants
Treatment is symptomatic only, not curative.
Viral – sometime treated with antivirals
Bacterial – can be treatment with antibiotics
Difficult to determine so often treat the most likely cause “empirical
therapy”.
Major inflammatory mediator in many allergic disorders
Allergic rhinitis (e.g., hay fever and mould and dust allergies)
Anaphylaxis
Angioedema
Drug fevers
Insect bite reactions
Urticaria (pale red, raised, itchy bumps)
histamine
Severe Allergic Reactions
Release of excessive amounts of histamine can lead to:
Constriction of smooth muscle, especially in the stomach and lungs
Vasodilatation and increased capillary permeability, movement of fluid out of the blood vessels and
into the tissues, and drop in blood pressure and edema
anaphylaxis
Drugs that directly compete with histamine for specific receptor sites
antihistamines
what are the histamine antagonists?
H1-antagonists
H2-antagonists
Examples: chlorpheniramine, fexofenadine (Allegra®), loratadine (Claritin®), cetirizine (Reactine®), desloratadine
(Aerius®), diphenhydramine (Benadryl®
H1-antagonists
Used to reduce gastric acid in peptic ulcer disease
Examples: cimetidine, ranitidine (Zantac®), famotidine (Pepcid AC®), nizatidine (Axid®)
H2-antagonists
what is the MOA of antihistamines?
Block action of histamine at H1-receptor sites
Binds with unoccupied receptors
Early treatment is key!
Effects on : CVS, Smooth muscle, Immune System
what are the 2 types of antihistamines?
traditional
nonsedating
brompheniramine, chlorpheniramine, dimenhydrinate,
diphenhydramine, and promethazine
traditional antihistamines
loratadine, cetirizine, and fexofenadine
nonsedating antihistamines
Older, Work both peripherally and centrally
Have anticholinergic effects, making them more effective than nonsedating
drugs in some cases
Examples: diphenhydramine (Benadryl), brompheniramine, chlorpheniramine,
dimenhydrinate (Gravol), promethazine
traditional antihistamines
Developed to eliminate unwanted adverse effects, mainly sedation
Work peripherally to block the actions of histamine; thus, fewer central
nervous system adverse effects
Longer duration of action (increases compliance with once-daily dosing)
Examples: loratadine (Claritin), cetirizine(Reactine), and fexofenadine (Allegra)
nonsedating peripherally acting antihistamines
what are the indications of antihistamines?
Management of: Nasal allergies, Seasonal or perennial allergic rhinitis (hay
fever), Allergic reactions, Motion sickness, Parkinson’s disease, Vertigo, Sleep
disorders, Sneezing and runny nose associated with ‘a cold’
what are the contraindications of antihistamines?
Known drug allergy, Acute-angle glaucoma, Cardiac disease, hypertension, Kidney
disease, Peptic ulcer disease, Seizure disorders, Benign prostatic hyperplasia, Pregnancy,
Bronchial asthma, chronic obstructive pulmonary disease (COPD)
Not to be used as sole drug therapy during acute asthmatic attacks
salbutamol or epinephrine should be used.
what are the AE of antihistamines?
Anticholinergic (drying) effects: most common
Dry mouth
Difficulty urinating
Constipation
Changes in vision
Cardiovascular, central nervous system, gastrointestinal, and other
effects
Drowsiness
Mild drowsiness to deep sleep
what are the 3 main types of decongestants?
adrenergics
anticholinergics
corticosteroids
what are the dose forms of decongestants?
oral
inhaled or topically applied
Prolonged decongestant effects; delayed onset
Effect less potent than topical
No rebound congestion
Exclusively adrenergics
Example: pseudoephedrine
oral decongestants
Prompt onset, Potent
Sustained use over several days causes rebound congestion, making the condition worse.
ephedrine, oxymetraxoline hydrochloride (Dristan), phenylephrine, and tetrahydrozoline
topical adrenergics
*Not associated with rebound congestion, Often used prophylactically to prevent nasal
congestion in patients with chronic upper respiratory tract symptoms
Intranasal anticholinergic: ipratropium (Atrovent®)
inhaled intranasal- steroids and anticholinergic drugs
what are intranasal steroids?
beclomethasone dipropionate (Qvar®), budesonide (Rhinocort®),
flunisolide (Rhinalar®), fluticasone (Avamys®), triamcinolone (Nasacort®), mometasone
(Nasonex®)
what is the MOA of adrenergics?
Constrict small blood vessels that supply upper respiratory tract structures
As a result, these tissues shrink, and nasal secretions in the swollen mucous
membranes are better able to drain
what is the MOA of nasal steroids?
Anti-inflammatory effect
Work to turn off the immune system cells involved in the inflammatory response
Decreased inflammation results in decreased congestion.
what are the indications of nasal decongestants?
Relief of nasal congestion associated with: Acute or chronic rhinitis,
Common cold, Sinusitis, Hay fever, Other allergies
Reduce swelling of the nasal passage and facilitate visualization of
the nasal or pharyngeal membranes before surgery or diagnostic
procedures
what are the contraindications of nasal decongestants?
Drug allergy, Acute-angle glaucoma, Uncontrolled cardiovascular disease, hypertension,
Diabetes and hyperthyroidism, Prostatitis, Inability to close the eyes, History of
cerebrovascular accident or transient ischemic attacks, Cerebral arteriosclerosis, Long-
standing asthma, Benign prostatic hyperplasia, Diabetes
what are the AE of adrenergics and steroids?
Adrenergics: Nervousness, Insomnia, Palpitaiions, Tremors
Steroids: Local mucosal dryness and irritation
what are the interactions of nasal decongestants?
Systemic sympathomimetic drugs and sympathomimetic nasal
decongestants are likely to cause drug toxicity when given together.
Monoamine oxidase inhibitors and sympathomimetic nasal
decongestants raise blood pressure.
Ask if pregnant client is on Methyldopa
Urinary acidifiers and alkalinizers
Respiratory secretions and foreign objects are naturally removed by
the cough reflex.
Induces coughing and expectoration
Initiated by irritation of sensory receptors in the respiratory tract
cough physiology
what are the 2 types of coughs?
productive
nonproductive
congested; removes excessive secretions
productive cough
dry cough
nonproductive
Drugs used to stop or reduce coughing, Primarily used only for nonproductive coughs!
Opioid and nonopioid
May be used in cases when coughing is harmful
antitussives
what is the MOA for opioids?
Suppress the cough reflex by direct action on the cough centre in the medulla
They have analgesia effect.
Drying effect on the mucosa of the respiratory tract, increased viscosity of respiratory secretions,
reduction of runny nose and postnasal drip
Examples: codeine, hydrocodone
what is the MOA of nonopioids?
Suppresses cough reflex
Dextromethorphan: works in the same way
* Not an opioid, No analgesic properties, No central nervous system depression
what are the contrainidications of antitussives?
Drug allergy, Opioid dependency, Respiratory depression
what are the AE of antitussives?
diphenhydramine:
Sedation, dry mouth, and other anticholinergic effects
dextromethorphan
Dizziness, drowsiness, nausea
Opioids
Sedation, nausea, vomiting, lightheadedness, constipation
Drugs that aid in the expectoration (removal) of mucus
Reduce the viscosity of secretions
Disintegrate and thin secretions
Example: guaifenesin
expectorants
what is the MOA of expectorants?
Reflex stimulation: Irritation of the gastrointestinal tract; Loosening and thinning of
respiratory tract secretions.
Direct stimulation: The secretory glands are stimulated directly to increase their production
of respiratory tract fluids.
Final result: thinner mucus that is easier to remove
Drug Effects: By loosening and thinning sputum and bronchial secretions, the
tendency to cough is indirectly diminished.
Reduces symptoms of the common cold and recovery time
echinacea
what are the AE of echinacea?
Dermatitis
Gastrointestinal disturbance or vomiting
Dizziness
Headache
Unpleasant taste
