Upper Respi

Cards (19)

  • Antihistamines
    (H1 blockers or H1-receptor antagonists)
  • Antihistamines
    • Diphenhydramine
    • Chlorpheniramine
    • Clemastine fumarate
    • Azelastine
    • Cetirizine
    • Loratadine
  • First-Generation Antihistamines
    Diphenhydramine, Chlorpheniramine, Clemastine fumarate
  • Second-Generation Antihistamines
    Azelastine, Cetirizine, Loratadine
  • Mechanism of Action of Antihistamines
    1. Compete with allergy-liberated histamine for H1-receptor sites
    2. Occasionally, a patient may develop a tolerance to the antihistaminic effects; changing to another antihistamine is usually effective when this occurs
  • Therapeutic Outcome of Antihistamines
    Reduced symptoms of allergic rhinitis (e.g., rhinorrhea, lacrimation, itching, conjunctivitis)
  • Side Effects of First-Generation Antihistamines

    • Drowsiness, dizziness, fatigue, and disturbed coordination
    • Skin rashes and anticholinergic symptoms such as: dry mouth, urine retention, blurred vision, and wheezing may occur
  • Side Effects of Second-Generation Antihistamines

    • Little to no sedating effect
    • Fewer anticholinergic symptoms
  • Antitussives
    Act on the cough-control center in the medulla to suppress the cough reflex
  • Types of Antitussives
    • Nonopioid
    • Opioid
    • Combination preparations
  • Opioid Antitussives
    • Codeine
    • Guaifenesin
    • Guaifenesin 200 mg and Codeine 9 mg
  • Nonopioid Antitussives
    • Benzonatate
    • Dextromethorphan
  • Expectorants
    • Guaifenesin
    • Dextromethorphan
  • Mechanism of Action of Dextromethorphan
    1. Reduces the viscosity of tenacious secretions
    2. Acts as a nonopioid antitussive by changing a nonproductive cough to a less frequent, productive cough
    3. Acts directly on the MEDULLARY cough of the brain to depress the cough reflex, but it does NOT suppress respiration
  • Decongestants
    Sympathomimetic amines that cause local vasoconstriction, shrinking of the nasal mucous membranes and a reduction in fluid secretion (runny nose)
  • Mechanism of Action of Decongestants
    1. Shrinks the nasal mucosa by stimulating the alpha-adrenergic receptors in the nasal membranes
    2. Promotes drainage of the sinuses and improving airflow
    3. The advantage of oral decongestants is that they relieve nasal congestion for a longer period
  • Expectorants
    Loosen bronchial secretions so they can be eliminated by coughing
  • Guaifenesin
    The most common expectorant, used for the symptomatic relief of conditions characterized by mucus in the respiratory tract with a dry, nonproductive cough
  • Mechanism of Action of Guaifenesin
    1. Acts by enhancing the output of respiratory tract fluid
    2. The increased flow of secretions decreases mucus viscosity and promotes ciliary action
    3. A combination of ciliary action and coughing then expels the phlegm from the pulmonary system