CH 39: Drugs for Allergic Rhinitis and the Common Cold Flashcards
Drugs for Allergic Rhinitis and the Common Cold
H1 Receptor Antagonists – Antihistamine
Mast Cell Stabilizers
Intra-nasal Corticosteroids
Decongestants
Antitussives
Expectorants, mucolytics, and drugs for cystic fibrosis
jobs of the upper respiratory tract
warm, humidify, and clean the air before it enters the lungs
traps particulate matter and many pathogens, preventing them from being carried to bronchioles and alveoli, where they could access the capillaries of the systemic circulation.
mucous membranes of the URT are lined with ciliated epithelium, which traps and “sweeps” the pathogens and particulate matter posteriorly, where it is swallowed when someone coughs or clears the throat.
dynamic structure, richly supplied with vascular tissue that is controlled, in part, by the autonomic nervous system.
nasal mucosa
Activation of the sympathetic nervous system:
constricts arterioles in the nose, reducing the thickness of the mucosal layer. This serves to widen the airway and allow more air to enter.
Parasympathetic activation
Arterioles dilate and more mucus is
produced.
the administration of a sympathomimetic will:
shrink the nasal mucosa, relieving the nasal stuffiness associated with the common cold.
parasympathetic drugs cause:
increased blood flow to the nose, with increased nasal stuffiness and a runny nose as side effects.
inflammation of the nasal mucosa due to exposure to allergens
Allergic Rhinitis
Hayfever
symptoms of allergic rhinitis
resemble those of the common cold: tearing eyes,sneezing, nasal congestion, post-nasal drip, and itching of the throat.
preventers of allergic rhinitis
antihistamines,
intranasal corticosteroids,
leukotriene modifiers,
mast cell stabilizers.
relievers of allergic rhinitis
oral and intranasal decongestants
usually drugs from the sympathomimetic class.
Mediator of inflammation
Responsible for many of the symptoms of allergic rhinitis
histamines
where are histamines released
mast cells
basophils
what do histamines cause
cause itching, increased mucus secretion, and nasal congestion.
with more severe allergic states: bronchoconstriction, edema, hypotension, and other symptoms of anaphylaxis.
block all histamine
antihistamine
MOA and uses of H1 receptor antagonists
selectively block H1 at the receptor
allergy symptoms, motion sickness, and insomnia.
Most frequent use is for the treatment of allergies
Provide symptomatic relief
Used for cold and sinus problems when combined with decongestants and antitussives
Most effective for prophylaxis
anticholinergic effects of H1 receptor blockers
increased heart rate, urinary retention, constipation, blurred vision
diphenhydramine (1st gen antihistamine) therapeutic effects
Counteract the effects of histamine
Oral, po, IV, IM, topical uses