Pharm110 Chp 14 Antihistamines and Nasal Decongestants

Question 1

Antihistamines

Answer 1

Virus infections
Rhinovirus (Common cold)
Influenza virus
-Initiates the inflammatory response

Question 2

Common cold

Answer 2

The most common acute illness in the USA
Cough reflex
-Irritant stimulates sensory receptors
-Removes
Respiratory secretions
Foreign objects

Question 3

Inflammatory response

Answer 3

Mucosal irritation
Release of several inflammatory and vasoactive substances
-Histamine
-Dilating small blood vessels in the nasal sinuses
Produces nasal congestion

Question 4

Symptomatic treatment

Answer 4

Combined use of Antihistamines, nasal decongestants, antitussives and expectorants

Question 5

Allergic rhinitis

Answer 5

Immune response from contact with one or more environmental allergens with the nasal mucosa
Produces inflammatory response, initiated by release of histamine and other inflammatory mediators.
Histamines effects include
Vasodilation
Increased mucus production
Swelling
Congestion
Sneezing
Red eyes
Tearing

Question 6

Antihistamines process

Answer 6

Compete with histamine for receptor sites
H1 Histamine receptor (on cell membrane surfaces of arteriole and capillary cells)
The binding of H1 and H2 blockers to histamine receptors prevents histamine stimulation

Question 7

H1 antagonists

Answer 7

Effects
Antihistaminic
Mild anticholinergic (Drying)
Parasympathetic nervous system
Sedative

Question 8

Antihistamine cautions

Answer 8

Antihistamines
-May increase BP, monitor BP

Histamine effects

• Dilation
• Permeability (swelling)
• itching

Antihistamine effects

• Prevent dilation
• Prevent increased permeability
• Decrease itching

Question 9

Antihistamine uses

Answer 9

Nasal allergies
Seasonal or perennial allergic reactions
Allergic reactions
Motion sickness
More effective in prevention when given early

Question 10

Classes of Antihistamines

Answer 10

Two types
Traditional: sedating
Nonsedating (longer duration of action)

Traditional Drug examples
diphenhydramine (Benadryl)
chlorpheiramine (Chlor-Trimaton)

Nonsedating drug examples
fexofenadine (Allegra)
loratadine (Claritin)

Question 11

Antihistamine nursing implications

Answer 11

Assess allergy history
Contraindicated (Never use on patients with)
-Asthma attacks
-Chronic obstructive pulmonary disease
-Cardiovascular disease

Client education:

• Avoid driving or operating machinery
• Avoid CNS depressant drugs, e.g. opioids
• Avoid alcohol (CNS depressant).