Chapter 38- drugs for allergic thinitis and common cold

Question 1

common causes and symptoms of allergic rhinitis

Answer 1

• caused by EXPOSURE TO AN ALLERGEN (pollens from weeds, grasses, and trees; mold spores; dust mites; certain foods; animal dander
• tearing eyes, sneezing, nasal congestion, post-nasal drip, itching of the throat
• loss of taste or smell, sinusitis, chronic cough, hoarseness, middle ear infections in children

Question 2

H1 vs. H2 histamine receptors

Answer 2

• H1 receptors are the histamine receptors responsible for allergic symptoms
• H2 receptors are found in the gastric mucosa and are responsible for peptic ulcers

Question 3

H1-receptor antagonists/antihistamines

Answer 3

• block actions of histamine at H1 receptor and alleviate allergic symptoms
• treat allergies
• often combined with decongestants and antitussives in OTC cold and sinus medicines
• most effective when taken prophylactically to PREVENT symptoms
• cause typical anticholinergic effects- drying of mucous membranes, etc.

Question 4

antihistamines are mostly given orally but sometimes intranasally

Answer 4

-intranasal- applied locally to nasal mucosa…limited systemic absorption occurs

Question 5

two examples of H1 receptor antagonists/antihistamines

Answer 5

-Benadryl and Allegra

Question 6

intranasal corticosteroids

Answer 6

• often first line drugs in treatment of allergic rhinitis
• produce virtually no serious adverse effects
• intranasal corticosteroids decrease the secretion of inflammatory mediators, reduce tissue edema, and cause a mild vasoconstriction
• 2-3 weeks may be required to achieve peak response
• most effective when taken in advance of the allergen exposure

Question 7

drug example of intranasal corticosteroid

Answer 7

-Flovent (fluticasone)

Question 8

nasal decongestants

Answer 8

• either oral of intranasal
• INTRANASAL- produce few systemic effects; limited side effect is rebound congestion (hypersecretion of mucus and worsening nasal congestion once the drug effects wear off); should be used no longer than 3-5 days to prevent rebound congestion
• ORALLY- onset of action is much slower; less effective at relieving severe congestion

Question 9

sympathomimetic nasal decongestant

Answer 9

• pseudophedrine (Sudafed)
• oral
• often combined with antihistamines to control sneezing and tearing

Question 10

anticholinergic nasal decongestant

Answer 10

• Atrovent (ipratropium bromide)
• INTRANASAL
• no serious adverse effects

Question 11

what are the most effect antitussives?

Answer 11

opioid antitussives

• act by raising cough threshold in the CNS
• give cautiously to patients with asthma (bronchoconstiction may occur)
• may be combined with agents such as antihistamines, decongestants, or nonopioid antitussives

Question 12

most common NONOPIOID antitussive

Answer 12

• dextromethorphan
• acts on CNS to raise the cough threshold
• symptoms of abuse include slurred speech, dizziness, drowsiness, euphoria, and lack of motor coordination

Question 13

-expectorants and mucolytics

Answer 13

• expectorants are drugs that reduce the thickness or viscosity of bronchial secretions and increase mucus flow that can then be removed more easily by coughing
• mucolytics- break down the chemical structure of mucus molecules and mucus become more thin and easier to remove by coughing

Question 14

most common expectorant

Answer 14

guaifenesin (Robitussin)

-most effective in treating dry, nonproductive cough, but also may benefit patients with productive cough