H1 Receptor Antagonists Sedating |
|
|---|---|
| DIPHENHYDRAMINE | chlorpheniramine |
| acrivastine | dimenhydrinate |
| azelastine | hydroxyzine |
| brompheniramine | meclizine |
| clemastine | promethazine |
| cyclizine | |
| cyproheptadine | |
| olopatadine | |
H2 Receptor Atagonists Nonsedating Antihistamines |
|
| astemizole | fexofenadine |
| cetirizine | levocetirizine |
| desloratadine | loratadine |
Antihistamines are medications used to block the effects of histamine, a chemical released mainly by mast cells during allergic and inflammatory reactions.
1. Allergic conditions
Allergic rhinitis (hay fever)
Urticaria (hives)
Allergic conjunctivitis
Allergic skin reactions (itching, flushing)
2. Relief of symptoms caused by histamine
Itching (pruritus)
Sneezing
Runny nose (rhinorrhea)
Watery eyes
Skin swelling and redness
3. Motion sickness and vertigo
(primarily first-generation antihistamines)
Prevention and treatment of nausea and vomiting
Vestibular disorders
4. Sedation and sleep aid
(first-generation antihistamines due to CNS penetration)
Short-term treatment of insomnia
Pre-operative sedation (occasionally)
5. Adjunct in anaphylaxis
Used with epinephrine, not as a substitute
Helps relieve cutaneous symptoms (hives, itching)
First-generation (e.g., diphenhydramine): sedating, anticholinergic effects
Second-generation (e.g., loratadine, cetirizine): less sedating, preferred for chronic allergies
If you want, I can summarize the differences between H1 and H2 antihistamines or give common examples with side effects.