Respiratory Tract drugs: Antihistamines and Antitussives - Ch. 80

Question 1

What is a kind of cell that releases histamine (and other substances)?

Answer 1

Mast cells

Question 2

What does histamine cause?

Answer 2

Symptoms of allergic reactions

Question 3

What are antihistamines?

Answer 3

Histamine receptor antagonists
-Drugs that compete with histamine receptor site

Question 4

What are the 2 histamine receptor subtypes?

Answer 4

H1 (histamine1)
H2 (histamine2)

Question 5

What kind of histamine receptor do antihistamines bind to?

Answer 5

H1
-They are H1 antagonists
-Some also act as anticholinergic drugs

Question 6

What percent of the general population is sensitive to various environmental allergies?

Answer 6

10%-20%

Question 7

What are some histamine-mediated disorders?

Answer 7

Allergic rhinitis hay fever, mould and dust allergies)
Anaphylaxis
Angioedema
Drug fevers -usually young kids
Insect bite reactions
Urticaria (redness and itching)

Question 8

What is the mechanism of action of antihistamines?

Answer 8

Block of H1 receptors prevents the adverse consequences of histamine receptor stimulation

Question 9

What are the physiological effects of antihistamines?

Answer 9

Vasodilation
Increased GI and respiratory secretion
Increased capillary permeability

Question 10

What is the histamine action on small blood vessels?

Answer 10

Dilation and increased permeability
Swelling (fluid from plasma into interstitial fluid)

Question 11

What is the antihistamine effect on small blood vessels?

Answer 11

Reduce dilation of blood vessels
Reduce increased permeability of blood vessels

Question 12

What is the histamine action on exocrine glands?

Answer 12

Stimulate salivary, lacrimal and bronchial secretions

Question 13

What is the antihistamine effect on exocrine glands?

Answer 13

Reduce salivary, lacrimal and bronchial secretions

Question 14

What is another use for antihistamines?

Answer 14

Skin
-Reduce capillary permeability
-Wheal-and-flare formation
-Itching (pruritus)

Question 15

What are some palliative, not curative, treatments using antihistamines?

Answer 15

Nasal allergies
Seasonal or perennial allergic rhinitis (hay fever)
Allergic reactions
Motion sickness
Sleep disorders

Question 16

What are the 2 main types of Antihistamines?

Answer 16

Traditional (1950s)
Nonsedating/peripherally acting (1980s)

Question 17

What are traditional antihistamines?

Answer 17

older drugs
Antagonists of H1 receptors
Anticholinergic effects
Nighttime relief

Question 18

What do traditional antihistamines do when they act on peripheral H1 receptors?

Answer 18

Reduce respiratory/eye symptoms

Question 19

What do traditional antihistamines do when they act on central H1 receptors?

Answer 19

Cause sedation

Question 20

What are some examples of traditional antihistamines?

Answer 20

Diphenhydramine (Benadryl)
Chlorpheniramine

Question 21

Why are traditional antihistamines used as a sleep aid?

Answer 21

Because they cause sedation/drowsiness

Question 22

What is the anticholinergic effect of traditional antihistamines?

Answer 22

ACh on cell cholinergic receptors
-Parasympathetic NS action (peripheral)
-CNS (central)

Question 23

What does the anticholinergic effect of traditional antihistamines cause?

Answer 23

Drying effect that reduces nasal, lacrimal, salivary gland secretions
-runny nose, tearing, itching eyes
-Dry mouth (reduced saliva)
-Difficulty urinating
-Constipation
-Change sin vision (dilated pupils, blurred vision)

Question 24

What are nonsedating/peripherally acting antihistamines?

Answer 24

Developed to eliminate unwanted adverse effects, mainly sedation
Work peripherally

Question 25

What is the result of nonsedating/peripherally acting antihistamines working peripherally?

Answer 25

Fewer CNS adverse effects

Question 26

What is increased/longer in nonsedating antihistamines?

Answer 26

Longer duration of action increases adherance

Question 27

Examples of nonsedating/peripherally acting antihistamines?

Answer 27

Loratadine (Claritin) Desloratadine (Aerius) Fexofenadine (Allegra) Cetirizine (Reactin)

Question 28

What should the nurse do if the client is taking traditional antihistamines?

Answer 28

Instruct clients to report excessive sedation, confusion or hypotension Client should avoid driving or operating heavy machinery Do not consume alcohol or other CNS depressants

Question 29

What is coughing?

Answer 29

Respiratory secretions and foreign objects are naturally removed via cough reflex

Question 30

What is the cough reflex?

Answer 30

Induces coughing and expectoration Initiated by irritation of sensory receptors in the respiratory tract

Question 31

What are the two basic types of coughs?

Answer 31

1. Productive 2. Nonproductive

Question 32

What is a productive cough?

Answer 32

Congested, wet, removes excessive secretions

Question 33

What is a nonproductive cough?

Answer 33

Dry cough

Question 34

Is coughing always beneficial?

Answer 34

No sometimes can be harmful e.g, after hernia repair surgery

Question 35

What drugs are used to stop or reduce coughing?

Answer 35

Antitussives -Opioids -Othe ragents

Question 36

What is the only kind of cough that antitussives are used to treat?

Answer 36

ONLY Nonproductive coughs

Question 37

How are opioids antitussive?

Answer 37

Suppress the cough reflex Acts in cough centre of medulla

Question 38

Examples of antitussive opioids?

Answer 38

Codeine Hydrocodone

Question 39

What is a common over the counter (OTC) antitussive?

Answer 39

Dextromethorphan (Benylin)

Question 40

What is Dextromethorphan (Benylin)?

Answer 40

Synthetic opioid-like compound -Doesn't produce morphine-like effects tho

Question 41

What Traditional antihistamine is a non-opioid antitussive drug?

Answer 41

Diphenhydramine

Question 42

What are antitussives used for?

Answer 42

Used to stop cough reflex when the cough is nonproductive and/or harmful

Question 43

What adverse effects are associated with codiene as an antitussive?

Answer 43

Sedation, nausea, vomiting, lightheadedness, constipation -typical opioid effects

Question 44

What adverse effects are associated with dextromethorphan (antitussive)?

Answer 44

Dizziness, drowsiness, nausea -Less CNS effects than codeine

Question 45

What symptoms should be reported when using antitussives?

Answer 45

Cough lasts more than a week persisten headache fever rash