Antihistamines: Difference between revisions
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==Types== | ==Types== | ||
===H<sub>1</sub> antagonists=== | ===H<sub>1</sub> antagonists=== | ||
*First-generation (sedating | *First-generation (sedating; '''[[High-risk geriatric medication]]!''') | ||
**[[Diphenhydramine]] (Benadryl) | **[[Diphenhydramine]] (Benadryl) | ||
**[[Chlorpheniramine]] | **[[Chlorpheniramine]] | ||
Latest revision as of 23:17, 20 May 2026
Background
- Also known as histamine antagonists
- In common use, the term antihistamine refers only to compounds that inhibit action at the H1 receptor (and not H2, etc.).
Types
H1 antagonists
- First-generation (sedating; High-risk geriatric medication!)
- Diphenhydramine (Benadryl)
- Chlorpheniramine
- Dimenhydrinate
- Doxylamine
- Hydroxyzine (Vistaril)
- Meclizine
- Second-generation (non-sedating, preferred)
- Cetirizine
- Levocetirizine
- Loratadine (Claritin)
- Desloratadine
- Fexofenadine (Allegra)
- Azelastine
H2 antagonists
Indications
- H1 antagonists
- H2 antagonists
Side Effects
- Sedation
- Second-generation antihistamines cross the blood–brain barrier to a much lower degree (therefore are less sedating), however high doses can still induce the drowsiness