Source 出处 · Taiping Huimin Hejiju Fang · Doses are not given here: they are set by a licensed practitioner for the individual.
Safety. Zi Xue is recorded in the Taiping Huimin Hejiju Fang. It is one of the three cool-opening treasures, and it is the one whose classical ingredient list opens with gold. The list then runs through minerals — gypsum, calcite, magnetite, talc, niter, Glauber's salt — before it reaches aromatic and animal substances. The name, purple snow, is usually explained by the appearance of the finished powder. Taken together, the list is a fair picture of what a Song official formulary was willing to put into a preparation meant for a person who was burning with fever and no longer fully conscious.
And that is the presentation: high fever with convulsion, delirium, clouded spirit. In a modern setting this is not a category that can be worked through at home. Fever with altered consciousness or with a seizure is a time-critical emergency. Meningitis and encephalitis kill on a timescale of hours, and the treatment that changes the outcome is given in the first hours, after lumbar puncture and imaging, not after a pattern has been assigned. Febrile seizure in a young child is common and usually benign, but that is a conclusion reached after the child has been seen, not before. Status epilepticus — a seizure that does not stop — is a neurological emergency in its own right.
Two ingredients deserve to be named directly, because the modern record on them is not a matter of opinion. The classical list contains aristolochia root, a plant of the genus Aristolochia that contains aristolochic acid: a cause of aristolochic acid nephropathy and of urothelial carcinoma, and the reason aristolochic acid-containing herbs have been withdrawn or restricted in many countries. Modern manufacture commonly substitutes a costus-type wood instead. The library records here only that the original text lists the former; it does not endorse it. Cinnabar is mercuric sulfide, a cumulative toxin. Talc is a mineral for which asbestos contamination has been a standing quality concern in pharmaceutical use. Niter and Glauber's salt add a substantial mineral and electrolyte load — relevant in anyone with impaired renal function, and in children.
The animal materials carry trade and species restrictions rather than only pharmacological ones: rhinoceros horn prohibited in China since 1993, antelope horn from the saiga antelope which is CITES-listed, musk from a CITES-listed animal now often synthetic.
This page is not a recommendation. No dose, no preparation, no regimen, no claim of benefit. Pregnancy, children, older adults, renal or hepatic impairment, and concurrent anticonvulsant, sedative, diuretic or antihypertensive medication each remove the remaining room. If such a preparation has been taken and there is persistent vomiting, diarrhoea, tremor, confusion, or reduced urine output, treat it as an emergency and bring the packaging.
紫雪著录于《太平惠民和剂局方》，是「凉开三宝」中经典组成**首列黄金**的一首。其后是矿物一串：石膏、寒水石、磁石、滑石、硝石、芒硝，之后才到芳香与动物药。方名「紫雪」通常被解释为成粉后的色泽。整张清单大致就是一部宋代官修方书，为一位高热且神志已不清的人，愿意投进去的东西。
对应的证候是：高热、痉厥、谵语、神昏。在今天，这不是一个可以在家里自行推演的类别。发热伴意识改变或伴抽搐，属时间紧迫的急症；脑炎与脑膜炎的致死与致残以小时计，改变结局的处理在最初几小时内给予，前提是腰穿与影像，而不是先定一个证。幼儿热性惊厥常见且多为良性，但那是**看过之后**得出的结论，不是事前的前提。癫痫持续状态本身就是神经科急症。
两味要直接点名，因为现代记载不是见仁见智的问题。原方所记的**青木香**为马兜铃属植物，含马兜铃酸 —— 马兜铃酸肾病与尿路上皮癌的原因，也是多国禁用或限制含马兜铃酸药材的理由；现代生产多以木香类（云木香）代之。本库在此只记「原方如此记载」，不主张使用原方组成。朱砂是硫化汞，属蓄积性毒物。滑石是矿物，天然滑石的石棉伴生一直是药用质量上的争议点。硝石与芒硝带来可观的矿物与电解质负荷 —— 对肾功能受损者与儿童尤其相关。
动物药带来的不只是药理问题，还有物种与贸易限制：犀角贸易自 1993 年起在中国被禁止；羚羊角取自赛加羚羊，列入 CITES；麝香来自 CITES 所列物种，今多为人工麝香。
本页不是建议：不列用量、不列制法、不列服法，也不主张它对任何情况有益。妊娠、儿童、老年、肝肾功能受损，以及正在使用抗癫痫／镇静／利尿／降压类处方药，任何一项都足以抹去残余的空间。若已服用此类制剂并出现持续呕吐、腹泻、震颤、意识改变或尿少，属急症：立即就医，并把原包装带上。