Chlorcyclizines

Cetirizine is a second-generation peripherally selective antihistamine used to treat allergic rhinitis (hay fever), dermatitis, urticaria (hives), and runny nose. It is taken by mouth. Effects generally begin within thirty minutes and last for about a day. The degree of benefit is similar to other antihistamines such as diphenhydramine, which is a first-generation antihistamine.

Hydroxyzine, sold under the brand names Atarax and Vistaril among others, is an antihistamine medication. It is used in the treatment of itchiness, anxiety, insomnia, and nausea (including that due to motion sickness). It is used either by mouth or injection into a muscle.

Meclizine, sold under the brand name Bonine, among others, is an antihistamine used to treat motion sickness and dizziness (vertigo). It is taken by mouth. Effects generally begin in an hour and last for up to a day.

Buclizine is an antihistamine and anticholinergic of the diphenylmethylpiperazine group. It is considered to be an antiemetic, similar to meclizine.

Chlorcyclizine (Di-Paralene, Mantadil, Pruresidine, Trihistan) is a first-generation antihistamine of the diphenylmethylpiperazine group marketed in the United States and certain other countries. It is used primarily to treat allergy symptoms such as rhinitis, urticaria, and pruritus, and may also be used as an antiemetic. In addition to its antihistamine effects, chlorcyclizine has some anticholinergic, antiserotonergic, and local anesthetic properties. It has been studied as a potential treatment for various flaviviruses like hepatitis C and Zika virus.

Etodroxizine (INN; brand names Vesparax, Drimyl, Indunox, and Isonox) is a first-generation antihistamine of the diphenylmethylpiperazine group which is used as a sedative/hypnotic drug in Europe and South Africa.

Clocinizine is a first-generation antihistamine of the diphenylmethylpiperazine class. It is marketed in Spain in combination with phenylpropanolamine under the brand name Senioral.