Antihistamines and Antitussives

Question 1

What cells release histamines when exposed to an allergen?

Answer 1

Mast cells

Question 2

Antihistamines

Mechanism:

Answer 2

Mechanism: antagonist at H1 histamine receptors (competitive inhibitor) to prevent vasodilation (swelling) and bronchial secretions.
Also treat skin flares (mosquito bites) itching

Question 3

Traditional Antihistamines

Name one

Answer 3

Older drugs

Anticholinergic effects, causes sedation, drying to reduce secretions,

Diphenhydramine

Question 4

Nonsedating/Peripherally acting Antihistamines
Name one
Nursing implications

Answer 4

Newer drugs

Fewer CNS adverse effects (no drowsiness)
Longer duration of action

Loratadine

Do not consume alcohol!

Question 5

Antitussives
Name two groups
Indications:
Adverse effects of each group:

Answer 5

Opioids like codeine (cough reflex suppression)
- constipation
Dextromethorphan (not an opioid)
- drowsiness

NONproductive cough only!