Source 出处 · Shanghan Lun · Doses are not given here: they are set by a licensed practitioner for the individual.
Safety. Chaihu Guizhi Ganjiang Tang is Xiao Chai Hu Tang with four ingredients taken out and four put in. The removals are the ones that nourish and settle — pinellia, ginseng, fresh ginger, jujube. The additions are cinnamon twig, dried ginger, trichosanthes root and oyster shell. Reading the substitution tells you what the classical text thought was happening: not a deficiency to be supported, but a fluid problem — 饮, retained fluid — plus a dryness that needs fluid generated rather than poured in.
There is a detail in the source line that matters more than the formula. Shanghan Lun introduces it as 伤寒五六日，已发汗而复下之 — five or six days in, sweating has already been induced and then purging was applied. The state the formula addresses is described as the aftermath of treatment. So is Ganjiang Huangqin Huanglian Renshen Tang in this batch (医复吐下之, the practitioner then applied emesis and purgation again), and so is Mahuang Shengma Tang (大下后, after drastic purging). Three of the four formulas here take a treatment-caused deterioration as their starting point. That is worth sitting with: the classical corpus recorded iatrogenesis as a clinical category, and the modern habit is to skip over that half of the sentence.
What the text lists is a cluster, not a disease. Fullness and slight binding in the chest and flanks, difficult urination, thirst without vomiting, sweating confined to the head, alternating chills and fever, and irritability. Each of those has a modern differential that is not optional. Alternating chills and fever — the signature item — is a fever pattern, and a fever pattern is investigated: malaria, bacteraemia and endocarditis, tuberculosis, lymphoma, brucellosis, cholangitis, deep abscess, and drug fever.
Two of the signs belong together and are better known from another line. 但头汗出 together with 小便不利 and thirst is the combination the classical texts repeatedly associate with jaundice — damp-heat trapped inside, the sweat stopping at the neck. Today that pairing is a bilirubin and liver function test, and a right upper quadrant ultrasound if the numbers move. The point is not that the old description was wrong; it is that what took careful observation to notice in the second century takes a blood test now, and the blood test is the thing that changes management.
Thirst and reduced urine output carry their own lists: diabetes mellitus and diabetes insipidus, hypercalcaemia, dehydration, diuretics, anticholinergics, and Sjögren's. Reduced output in an older man is often prostatic; in anyone it can be acute kidney injury, and acute kidney injury has a cause that is worth finding.
The safety notes for this formula are specific. 栝楼根 is trichosanthes root, sold as 天花粉 — the root of Trichosanthes kirilowii. It is not the fruit (瓜蒌), not the seed (瓜蒌仁), and not pollen, whatever the name suggests. The protein isolated from it, trichosanthin, was developed and used to terminate pregnancy and to treat ectopic pregnancy; injections of it have recorded anaphylactic shock. Pregnancy is therefore an absolute exclusion for this formula, and not a matter of degree. 牡蛎 is oyster shell, essentially calcium carbonate, a mineral product in which shellfish can accumulate heavy metals from the water they grew in. 甘草 over time is a real pharmacological agent: glycyrrhizin inhibits 11β-HSD2 and produces a pseudohyperaldosteronism of hypertension, hypokalaemia and oedema, in severe cases hypokalaemic myopathy and rhabdomyolysis; alongside a diuretic or digoxin, the potassium loss is the mechanism that kills. 桂枝 is cassia cinnamon bark, and cassia species carry appreciable coumarin, hepatotoxic at sustained intake. 黄芩 is Scutellaria baicalensis and must not be confused with American skullcap (Scutellaria lateriflora); baicalensis-containing supplements appear in liver injury case series, frequently entangled with adulteration and misidentification. 柴胡 is Bupleurum: species substitution is documented, Bupleurum longiradiatum is toxic and must not appear, and Bupleurum-containing formulae were implicated in interstitial pneumonia in Japan, mostly together with interferon and in people with pre-existing lung disease. 干姜 is dried ginger, not fresh ginger and not galangal.
This entry records what the formula is recorded for. It is not a recommendation to use it, and nothing here is a treatment plan.
柴胡桂枝干姜汤就是小柴胡汤去掉四味、加上四味。去掉的是补与降的那一组（半夏、人参、生姜、大枣），加上的是桂枝、干姜、栝楼根、牡蛎。看加减就能看出古典文献把它当成什么问题：不是虚而要补，是饮与渴 —— 有水饮停留，又有津液不能上承。
但这一条最值钱的不是方，是条文的前半句：《伤寒论》写的是「伤寒五六日，已发汗而复下之」。也就是说，这首方所处理的局面，是**治完之后**的局面。本批的干姜黄芩黄连人参汤（「医复吐下之」）与麻黄升麻汤（「大下后」）同样如此 —— 四首里有三首把「治疗之后变糟」写进了适应症本身。古典文献把医源性恶化当成一类临床情形记录在案，而今天的读者往往跳过这半句。
条文列的是一组症候群，不是一种病：胸胁满微结、小便不利、渴而不呕、但头汗出、往来寒热、心烦。每一项都有今天必须走的鉴别：往来寒热是发热型式，要查疟疾、菌血症与感染性心内膜炎、结核、淋巴瘤、布鲁氏菌病、胆管炎、深部脓肿与药物热；渴与小便不利要查糖尿病与尿崩症、高钙、脱水、利尿剂、抗胆碱药与干燥综合征；老年男性排尿困难常见于前列腺，而任何人的尿量减少都可能是急性肾损伤，且急性肾损伤是有原因可找的。
有两项必须合看：**「但头汗出＋小便不利＋渴」正是古典文献反复与黄疸并提的那一组**（湿热郁蒸、汗出剂颈而还）。今天这一组是一张胆红素与肝功化验单，数字动了就加做右上腹超声。要点不是古人看错了，而是公元二世纪需要细察才能发现的东西，现在一张血检就能看见，而这张血检才会改变处置。
安全：**栝楼根即天花粉**，是栝楼（Trichosanthes kirilowii）的根，**既不是瓜蒌（果实）、也不是瓜蒌仁（种子）、更不是花粉**；从其中分离出的天花粉蛋白曾被开发用于终止妊娠与异位妊娠，注射制剂有过敏性休克记载 —— 故孕期对本方是绝对排除项，没有「少量」这一说。牡蛎是贝壳＝碳酸钙类矿物药，贝壳类可蓄积重金属。甘草长期即实效药：甘草酸抑制 11β-HSD2 造成假性醛固酮增多症（高血压、低钾、水肿，重者低钾性肌病与横纹肌溶解），与利尿剂／地高辛叠加时低钾是致命机制。桂枝为桂皮类树皮，含相当量香豆素，持续摄入有肝毒性。黄芩是 Scutellaria baicalensis，**不可与美黄芩（Scutellaria lateriflora）混同**，含黄芩属的补充剂有肝损伤病例系列且常牵涉掺伪与误判。柴胡存在品种混乱，**大叶柴胡有毒不可入药**，含柴胡制剂在日本曾牵涉间质性肺炎（多与干扰素合用、且多用于已有肺病者）。干姜是干品生姜，**不等于生姜，也不等于高良姜**。
本条目只记录文献所载，不构成使用建议，也不构成任何处置方案。