Antihistamine brand and generic names
The tables focus on H1 antihistamines. H2 blockers such as famotidine belong to a different group and are not part of this allergy-name list.
First-generation oral examples
| Brand name | Generic name | Class or type |
|---|---|---|
| Benadryl (oral allergy products) | diphenhydramine | Antihistamines |
| Atarax / Vistaril | hydroxyzine | Antihistamines |
Atarax is a historical hydroxyzine hydrochloride brand; Vistaril is associated with hydroxyzine pamoate. Keep the salt when identifying a specific formulation.
Second-generation oral examples
| Brand name | Generic name | Class or type |
|---|---|---|
| Zyrtec | cetirizine | Antihistamines |
| Claritin | loratadine | Antihistamines |
| Xyzal | levocetirizine | Antihistamines |
| Allegra | fexofenadine | Antihistamines |
A nasal antihistamine example
| Brand name | Generic name | Class or type |
|---|---|---|
| Astepro | azelastine | Antihistamines |
Astepro is an azelastine nasal product. Route is a separate detail from the generic name and drug class.
Understanding antihistamines
H1 identifies the histamine receptor family these examples act on. First-generation and second-generation are useful subdivisions within H1 antihistamines. They are not the same distinction as H1 versus H2.
First-generation agents such as diphenhydramine and hydroxyzine tend to cause more sedation than newer oral H1 antihistamines. Second-generation does not mean that drowsiness is impossible. Use the generation as an organizing feature, not a guarantee about how a particular person will respond.
An allergy-product shelf can contain antihistamines, corticosteroids, decongestants, and combinations. Astepro—azelastine is an antihistamine; Flonase—fluticasone propionate is a corticosteroid. Sharing a nasal route or an allergy-related brand message does not establish the same drug class.
Naming patterns and memory tips
Do not rely on one ending to find every antihistamine. Cetirizine and levocetirizine form a useful spelling pair, while loratadine, fexofenadine, diphenhydramine, and hydroxyzine need their own brand associations.
For each name, recall the brand and generic first, then add generation or route when relevant. For example, Zyrtec—cetirizine belongs with the second-generation oral examples, while Astepro—azelastine adds a nasal-product distinction. Keeping these as separate questions prevents a recognizable brand from standing in for the ingredient name.
Commonly confused antihistamine names
Zyrtec and Xyzal
Zyrtec pairs with cetirizine; Xyzal pairs with levocetirizine. The longer generic is not simply another spelling for cetirizine. Keep both complete names in a mixed study set.
Claritin and Claritin-D
Claritin pairs with loratadine. Claritin-D adds pseudoephedrine, a decongestant. The D is a useful reminder in this product family, but the full ingredient list is the reliable way to identify a combination.
Hydroxyzine and hydralazine
Hydroxyzine is an antihistamine. Hydralazine is a vasodilator. Their similar beginnings are a spelling trap; neither their classes nor their brand associations are the same.