Antihistamines Flashcards
Antihistamines
Drug Names
“amine”
-diphenhydramine
“ine”
- Hydroxyzine
- Meclizine
- Promethazine
- AzelastineCetirizine
- Fexofenadine
- Levocetirizine
- Loratadine
Antihistamines
Indications
Seasonal and perennial allergic rhinitis
allergic conjunctivitis
uncomplicated urticaria
angioedema
Antihistamines
Actions
Blocks release or action of histamine at histamine-1 receptor sites
Decreases allergic response
Anticholinergic and antipruritic effects
Antihistamines
Contraindications and Cautions
Contraindication:
Pregnancy and lactation
Caution:
- renal/hepatic impairment
- history of arrhythmias
Antihistamines
Adverse effects
Drowsiness and sedation
Anticholinergic effects: drying (respiratory and GI), nausea, dysuria, urinary hesitancy
Antihistamines
Drug-drug interactions
Varies based on the drug
What is histamine?
Histamine is a chemical released during inflammation
Increases secretions and narrows airways
Antihistamine would do the opposite
