The test, called Simons test, is performed by adding 1 volume of a solution of sodium nitroprusside and acetaldehyde in deionized water to a suspected drug, followed by the addition of 2 volumes of an aqueous sodium carbonate solution. The test turns blue for some secondary amines. The most common secondary amines encountered in forensic chemistry include 3,4-methylenedioxymethamphetamine (MDMA, the main component in Ecstasy) and phenethylamines such as methamphetamine. Sodium nitroprusside is also useful in the identification the mercaptans (thiol groups) in the nitroprusside reaction. History
Sodium nitroprusside is primarily used as a vasodilator. It was first used in human medicine in 1928. By 1955, data on its safety during short-term use in people with severe hypertension had become available. Despite this, due to difficulties in its chemical preparation, it was not finally approved by the US FDA until 1974 for the treatment of severe hypertension. By 1993, its popularity had grown such that total sales in the US had totalled US$2 million. == References ==
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.