Although hydroxyzine has a long elimination half-life and produces antihistamine for as long as 24 hours, the CNS effects of hydroxyzine and other antihistamines with long half-lives seem to diminish after 8 hours.Administration in geriatrics differs from the administration of hydroxyzine in younger patients; according to the FDA, there have not been significant studies made (2004), which include population groups over 65, which provide a distinction between elderly aged patients and other younger groups. Hydroxyzine should be administered carefully in the elderly with consideration given to possible reduced elimination. Chemistry
Hydroxyzine is a member of the diphenylmethylpiperazine class of antihistamines. Hydroxyzine is supplied mainly as a dihydrochloride salt (hydroxyzine hydrochloride) but also to a lesser extent as an embonate salt (hydroxyzine pamoate). The molecular weights of hydroxyzine, hydroxyzine dihydrochloride, and hydroxyzine pamoate are 374.9 g/mol, 447.8 g/mol, and 763.3 g/mol, respectively. Due to their differences in molecular weight, 1 mg hydroxyzine dihydrochloride is equivalent to about 1.7 mg hydroxyzine pamoate. Analogues
Analogues of hydroxyzine include buclizine, cetirizine, cinnarizine, cyclizine, etodroxizine, meclizine, and pipoxizine among others. Synthesis
Hydroxyzine is synthesized by the alkylation of 1-(4-chlorobenzhydryl)piperazine with 2-(2-chloroethoxy)ethanol:

Society and culture
Brand names
Hydroxyzine preparations require a doctors prescription. The drug is available in two formulations, the pamoate (anxiolytic) and the dihydrochloride or hydrochloride salts (antihistamine). Vistaril, Equipose, Masmoran, and Paxistil are preparations of the pamoate salt, while Atarax, Alamon, Aterax, Durrax, Tran-Q, Orgatrax, Quiess, and Tranquizine are of the hydrochloride salt. References
External links
"Hydroxyzine". Drug Information Portal. U.S. National Library of Medicine.
Chronic atrophic rhinitis, or simply atrophic rhinitis, is a chronic inflammation of the nose characterised by atrophy of nasal mucosa, including the glands, turbinate bones and the nerve elements supplying the nose. Chronic atrophic rhinitis may be primary and secondary. Special forms of chronic atrophic rhinitis are rhinitis sicca anterior and ozaena. It can also be described as the empty nose syndrome. Signs and symptoms
It is most commonly seen in females. It is reported among patients from lower socioeconomic groups. The nasal cavities become roomy and are filled with foul smelling crusts which are black or dark green and dry, making expiration painful and difficult. Microorganisms are known to multiply and produce a foul smell from the nose, though the patients may not be aware of this, because the nerve endings (responsible for the perception of smell) have become atrophied. This is called merciful anosmia. Patients usually complain of nasal obstruction despite the roomy nasal cavity, which can be caused either by the obstruction produced by the discharge in the nose, or as a result of sensory loss due to atrophy of nerves in the nose, so the patient is unaware of the air flow. In the case of the second cause, the sensation of obstruction is subjective. Bleeding from the nose, also called epistaxis, may occur when the dried discharge (crusts) are removed. Septal perforation and dermatitis of nasal vestibule can occur. The nose may show a saddle-nose deformity.