Library

In the syndrome of Chaihu Tang (Bupleurum Decoction), there are cases where taking Xiao Chaihu Tang (Minor Bupleurum Decoction) alone cannot cure the disease, and only Zhida Chaihu Tang (Major Bupleurum Decoction) can achieve a cure. This is because the pathogenic factor desires to utilize the pivot function of Shaoyang (Lesser Yang) to move outward but is obstructed by the closing function of Yangming (Greater Yang). Therefore, it is appropriate to combine agents that open and descend Yangming Qi with Xiao Chaihu Tang.

The original text of *Shanghan Lun* (Treatise on Cold Pathogenic Diseases) states: "In Taiyang (Greater Yang) disease, after more than ten days, if two or three purgative treatments were mistakenly applied, and after four or five days the Chaihu syndrome persists, first administer Xiao Chaihu Tang. If vomiting continues incessantly, there is urgency and distress in the epigastrium, and a sense of depression with slight irritability, indicating the pathogen has not resolved, administer Zhida Chaihu Tang. Purging will lead to recovery."

[Formula for Zhida Chaihu Tang] Chai Hu (Radix Bupleuri) half jin, Huang Qin (Radix Scutellariae) three liang, Shao Yao (Radix Paeoniae Rubra) three liang, Ban Xia (Rhizoma Pinelliae) half sheng (washed), Sheng Jiang (Rhizoma Zingiberis Recens) five liang (sliced), Zhi Shi (Fructus Aurantii Immaturus) four liang (stir-fried), Da Zao (Fructus Jujubae) twelve pieces (torn).

Take the above seven ingredients, add one dou and two sheng of water, decoct to obtain six sheng, remove the dregs, and decoct again. Take one sheng warm, three times daily. Another version includes Da Huang (Radix et Rhizoma Rhei) two liang.

Zhida Chaihu Tang in *Shanghan Lun* is a formula for treating Shaoyang syndrome complicated by Yangming involvement. When there is heat in the Yangming Stomach Fu organ, and the Shaoyevil pathogen carries this heat upward, it results in incessant vomiting, epigastric urgency, and mental depression with slight irritability. The intention was to use Xiao Chaihu Tang to extract the Shaoyang pathogen, allowing it to penetrate the diaphragm and emerge superiorly. However, fearing that Ren Shen (Radix Ginseng) would tonify the Stomach and assist the heat, Ren Shen was removed, and Da Huang was added to descend the heat. The coordination of herbs in this formula is distinct and effective, which is why it is regarded as an invincible army. Later generations, fearing the fierce nature of Da Huang, replaced it with Zhi Shi. When the formula proved ineffective, they had no choice but to add Da Huang back, yet completely forgot to remove Zhi Shi. This explains the origin of Zhida Chaihu Tang having versions with or without Da Huang. How do I know this? Because the disease indicated by this formula suits Da Huang but not Zhi Shi. In this formula, Chai Hu is the principal herb, originally intended to ascend and extract the Shaoyang pathogen through the diaphragm. Fearing its power might be too weak to reach the target directly, Ren Shen was used in Xiao Chaihu Tang to assist. Now, since the syndrome involves Yangming, Ren Shen is avoided to prevent assisting the heat, and Da Huang is added to guide the Yangming heat downward, treating both Yangming and Shaoyang simultaneously. However, since the formula is named "Major" Chaihu, its primary focus is Shaoyang. Without the assistance of Ren Shen, if both Da Huang and Zhi Shi are used together, they break blood and Qi respectively. Even with Chai Hu present, can it still treat the lingering Chaihu syndrome? Although Da Huang is a purgative, its action leans toward the Blood level, causing little damage to the Qi level, thus conflicting less with Chai Hu. In contrast, Zhi Shi damages the highest Qi in the chest (Zong Qi), making it clearly unsuitable for concurrent use with Chai Hu. I surmise that originally, only Da Huang was added to this formula. Later users, fearing Da Huang's intensity, substituted it with Zhi Shi. When ineffective, they re-added Da Huang but forgot to remove Zhi Shi. This ambiguity leads to confusion among practitioners. Henceforth, my colleagues should adopt the fixed prescription of adding Da Huang and removing Zhi Shi.

Ultimately, the Qi transformation differs between ancient and modern times, and human constitutions vary. Using Zhida Chaihu Tang today, neither Zhi Shi nor Da Huang should be used lightly. I will illustrate this with two cases.

Mr. Liu, a county scholar, invited me to treat his daughter, who married into a local family and faced domestic discord. In late autumn, she contracted wind-cold. Local doctors failed to cure her. After nearly ten days, she presented with alternating chills and fever, severe chest fullness and irritability, frequent vomiting, and a wiry, long, and forceful pulse. I told Mr. Liu, "This is a Zhida Chaihu Tang syndrome. Previous doctors did not recognize this treatment method, hence the failure." Mr. Liu agreed. I prescribed: Chai Hu 4 qian, Huang Qin, Shao Yao, Ban Xia each 3 qian, Sheng Shi Gao (Gypsum Fibrosum) 1.5 liang (crushed), Zhu Ru (Caulis Bambusae in Taeniam) 4 qian, Sheng Jiang 4 slices, Da Zao 4 pieces. Mr. Liu questioned, "Zhida Chaihu Tang originally contains Da Huang and Zhi Shi. Removing them and adding Shi Gao and Zhu Ru—will the medicinal strength be too weak to work?" I replied, "Medicine cures based on syndrome differentiation, not just strength. Take it boldly; if it fails, I bear responsibility." The patient trusted me and took one dose. Soon, she felt a pushing sensation, her chest opened up, and vomiting/irritability ceased. Mr. Liu asked, "Why such rapid effect despite weaker ingredients?" I explained, "Patients with Shaoyang disease often have prior Liver-Gallbladder stagnation, which attacks the Spleen-Stomach. As Yangming pathogen enters the Fu and mixes with Shaoyang, heat expands upward, disturbing the Heart, causing irritability and fullness. Xiao Chaihu Tang (without Ren Shen) soothes Liver-Gallbladder. Heavy Shi Gao clears Fu heat, preventing upward disturbance. Zhu Ru aids the Stomach and stops vomiting. This synergy causes rapid recovery."

Another case: A man over twenty, constitutionally weak, contracted cold while traveling in early summer. After ten days of unsuccessful treatment by others, I examined him. His father was decocting exterior-releasing herbs. I identified Baihu Tang (White Tiger Decoction) syndrome and forbade those herbs. Requesting a new prescription, I considered his weakness and mental strain. While Baihu Tang usually includes Ren Shen for deficiency, his father was overly cautious; adding Ren Shen would require more Shi Gao, potentially scaring him. Since he hadn't sweated or been purged, and lacked thirst, I believed Baihu Tang without Ren Shen would suffice. I prescribed Baihu Tang with Sheng Shi Gao 2 liang. His father thought it too much. I said, "I reduced it due to your caution, not because it's excessive." Noticing a rapid pulse, I added Sheng Di Huang (Radix Rehmanniae Preparata) 1 liang to nourish Yin. He was to take two bowls, divided twice. If fever persisted and stool remained normal, repeat the dose.

After I returned home, he took only one dose. Fever dropped 80-90%, but residual heat remained, so he stopped. Ten days later, constipation and mild leg swelling occurred. He planned to summon me again. A friend, knowing some medicine, claimed the swelling was caused by the heavy Shi Gao. His father believed this and hired another doctor. Seeing constipation, the new doctor prescribed purgatives with Da Huang 8 qian. After ingestion, the patient lost speech. His father summoned me urgently, but he died before I arrived. The constipation and swelling resulted from stopping treatment prematurely while residual heat lingered. Poor care followed by wrong medication led to fatal errors. Had he listened to me, either Baihu Tang or Baihu Jia Ren Shen Tang (White Tiger Decoction plus Ginseng) with heavier Shi Gao could have cleared heat via cool-moistening properties, unblocking stool and resolving swelling naturally. This case shows that using Da Huang in Zhida Chaihu Tang is inferior to using Shi Gao (heavy Baihu Tang can substitute Chengqi Tang functions, as discussed previously). When I was young, doctors trusted Wu Keyou, using large doses of Chengqi Tang for Yangming Fu excess with great success. By my time, these same methods often failed. Only ten years passed then, let alone a thousand since Han dynasty. Though known for treating cold-warm diseases, I use Baihu Tang several times a month, but rarely touch Chengqi Tang all year.