4-羟基甲苯噻嗪是α| 2 |-肾上腺素能受体激动剂甲苯噻嗪的主要代谢产物，苯胺衍生物是用作动物性镇静剂的苯胺衍生物。4-羟基甲苯噻嗪对于在兴奋剂对照实验中鉴定赛拉嗪在马匹系统中的初始存在特别重要。 4-Hydroxy Xylazine is a major metabolite of the α|2|-adrenergic receptor agonist Xylazine, an aniline derivative used as a zoological sedative. 4-Hydroxy Xylazine is particularly important as a marker for identifying the initial presence of Xylazine in the systems of horses in doping control experiments.