Table 3.

Oral H-1 antihistamines.

Generic Name	Common Brand Name	Generation
Brompheniramine	Dimetapp	First
Carbinoxamine	Arbinoxa, Karbinal ER, Palgic, Ryvent	First
Cetirizine	Zyrtec	Second*
Chlorpheniramine	Allerest, Contac, Triaminic	First
Clemastine	Tavegyl	First
Cyproheptadine	Periactin	First
Desloratadine	Clarinex	Second
Dimenhydrinate	Dramamine	First
Diphenhydramine	Benadryl, Simply Sleep, Sominex, Unisom, ZZZQuil	First
Doxylamine	Unisom	First
Fexofenadine	Allegra	Second
Hydroxyzine	Atarax	First
Levocetirizine	Xyzal	Second
Loratadine	Alavert, Claritin	Second
Meclizine	Antivert, Bonine	First
Promethazine	Phenergan	First
Triplodine	Histex	First

Oral H-1 antihistamines that are available in the United States by classification as first (crosses blood–brain barrier) or second (does not significantly cross blood–brain barrier) generation. *While categorized as a second-generation antihistamine, cetirizine does cross the blood–brain barrier and can cause sedation in some patients, although less than would be expected for a true first-generation antihistamine.⁷⁰