（仲景）
治太阳病六七日，表证仍在，脉微而沉，反不结胸，其人发狂者，以热在下焦，少腹当
硬满。小便自利者，必有蓄血，令人善忘，所以然者，以太阳随经，瘀热在里故也（表证仍
在，谓发热恶寒头痛项强未罢也。太阳为经，膀胱为腑，此太阳热邪随经入腑，热与血搏，
故为蓄血。脉沉为在里，表证仍在，则邪气犹浅，不结于胸中而发狂。经曰∶热结膀胱，其
人如狂。又曰∶血并于下，乱而喜忘。少腹硬满而小便不利者，为溺涩；硬满而小便利者，
为蓄血。《准绳》曰∶玩仍在二字，则邪气为不传里，非犹浅也。膀胱为太阳本经，曰热结
下焦，曰少腹硬满，曰小便自利，皆膀胱之证，故总结曰∶随经瘀热也。在里二字，乃随经
膀胱之里，非三阴之里也。按∶太阳在阳在表，即有沉紧、沉滑之脉，皆不得以里、阴名之）。
水蛭（三十个。猪脂熬黑） 虻虫（三十个。去头足翅） 桃仁（二十枚。去皮尖。研）
大
此足太阳药也。成氏曰∶苦走血，咸渗血，虻虫、水蛭之苦咸以除蓄血；甘缓结，苦泄
热，桃仁、大黄之甘苦以下结热（程郊倩曰∶表证仍在，脉微而沉，是有表证而无表脉，热
在下焦可知，非桂枝所能散，桃仁承气所能攻。缘热结膀胱，与瘀热在里，邪有浅深，故桃
仁承气与抵当汤攻有缓急）。本方减水蛭十个。虻虫、桃仁各减五个，分为四丸，每水煮一
丸，名抵当丸∶治本病无善忘如狂之证者（水蛭即蚂蝗 。咸寒有毒，乃食血之虫，能通肝
经聚血，最难死，虽炙为末，得水便活，若入腹中，生子为患，田泥和水饮下之；虻虫即蚊
虫，因其食血，故用以治血，二药险峻，世人罕用，故更制代抵当汤。吴鹤皋曰∶古人用蚊
虫、水蛭治血积，以其善吮血耳。若天鼠矢乃食蚊而化者也，当亦可以治血积，本草称其下
死胎，则其
附∶代抵当丸∶大黄（四两） 生地 归尾 桃仁 穿山甲 玄明粉（各一两） 桂（三
钱）。蜜丸（桃仁、归尾、生地润以通之，桂心热以动之，大黄、玄明粉苦寒咸寒以推荡之，
加穿山甲引之以
（张仲景）
治疗太阳病经过六七天，表证仍然存在，脉象微而沉，反而没有形成结胸证，病人出现发狂的症状，这是因为热邪在下焦，小腹部应当硬满。如果小便通畅自如的，必定有蓄血证，使人容易健忘。之所以这样，是因为太阳经的热邪随经络内传入腑，瘀热结聚在体内所致。（所谓“表证仍在”，是指发热、恶寒、头痛、项强等症状尚未消除。太阳主经，膀胱为腑，这是太阳的热邪随经络进入膀胱之腑，热与血相互搏结，所以形成蓄血证。脉象沉表示病位在里，既然表证仍在，说明邪气尚浅，不结聚于胸中却导致发狂。经典记载：“热结膀胱，其人如狂。”又说：“血并于下，乱而喜忘。”小腹部硬满且小便不利的，是溺涩；硬满而小便通利的，是蓄血。《准绳》说：玩味“仍在”这两个字，则邪气并非未传里，而是邪气并不浅。膀胱是太阳的本经，说“热结下焦”，说“少腹硬满”，说“小便自利”，都是膀胱的证候，所以总结说：“随经瘀热”。所谓“在里”，是指随经入膀胱之里，而不是三阴之里。按：太阳属阳、在表，即使出现沉紧、沉滑的脉象，都不能以里、阴来命名）。
水蛭（三十个。用猪脂熬至黑色） 虻虫（三十个。去掉头、足、翅） 桃仁（二十枚。去掉皮和尖，研碎）
大黄（四两。酒浸）
这是足太阳膀胱经的药物。成无己说：苦味走血分，咸味渗血分，虻虫、水蛭的苦咸之性可以消除蓄血；甘味缓急，苦味泄热，桃仁、大黄的甘苦之性可以下行结聚之热。（程郊倩说：表证仍在，脉微而沉，是有表证而无表脉，可知热在下焦，不是桂枝汤所能解散的，也不是桃核承气汤所能攻下的。因为热结膀胱与瘀热在里，邪气有浅深之分，所以桃核承气汤与抵当汤的攻下有缓急之别）。本方减去水蛭十个，虻虫、桃仁各减五个，分为四丸，每丸用水煮服，名为抵当丸：治疗上述疾病但没有健忘、发狂症状的患者（水蛭即蚂蝗，咸寒有毒，是食血的昆虫，最难杀死，即使烤干研末，遇水便复活，若进入腹中，生子为患，可用田泥和水调服解毒；虻虫即蚊类，因其食血，故用来治血证，这两种药性险峻，世人很少使用，所以另外制成代抵当汤。吴鹤皋说：古人用水蛭、虻虫治疗血积，因为它们善于吮吸血分。如果天鼠屎是吃蚊子化生的，也应该可以治疗血积，本草称它能下死胎，那么它……）。
附：代抵当丸：大黄（四两） 生地 归尾 桃仁 穿山甲 玄明粉（各一两） 桂心（三钱）。蜜丸（桃仁、归尾、生地滋润以通络，桂心温热以动血，大黄、玄明粉苦寒咸寒以推荡积滞，加穿山甲引药直达病所……）
(Zhang Zhongjing)
Treating Taiyang disease (Taiyang disease, a syndrome caused by pathogenic factors affecting the Taiyang channel) after six or seven days, where the exterior syndrome (biao zheng, symptoms such as fever and aversion to cold indicating pathogen at the surface) still persists, the pulse is faint and deep. There is no Jie Xiong (Jie Xiong, chest binding syndrome characterized by fullness and pain in the chest) formation. The patient exhibits mania (fa kuang, manic behavior due to heat disturbing the mind). This is because heat resides in the Lower Jiao (Lower Jiao, the lower part of the torso containing the bladder and intestines), and the lower abdomen should be hard and full. If urination is normal and free, there must be Blood Stasis accumulation (Xu Xue, accumulation of stagnant blood). This causes forgetfulness (shan wang). The reason for this is that the heat of the Taiyang channel follows the meridian into the interior, resulting in stasis-heat lodged within (Yu Re Zai Li). ("Exterior syndrome still persists" refers to the unresolved symptoms of fever, aversion to cold, headache, and neck stiffness. Taiyang governs the channels, and the Bladder is its associated organ. Here, Taiyang heat pathogens follow the meridians into the Bladder organ, where heat and blood contend, thus forming Blood Stasis accumulation. A deep pulse indicates an interior location. Since the exterior syndrome persists, the pathogen is still shallow; it does not bind in the chest but causes mania. The Classics state: "Heat binds in the Bladder, the person becomes like mad." Also: "Blood congregates below, causing disorder and forgetfulness." Hardness and fullness of the lower abdomen with difficulty in urination indicate urinary obstruction; hardness and fullness with free urination indicate Blood Stasis accumulation. *Zhun Sheng* states: Considering the words "still persists," the pathogen has not failed to enter the interior, nor is it merely shallow. The Bladder is the primary organ of the Taiyang channel. Statements regarding "heat binding in the Lower Jiao," "hardness and fullness of the lower abdomen," and "free urination" are all syndromes of the Bladder. Thus, it is summarized as "meridian-following stasis-heat." The term "in the interior" refers to the interior of the Bladder following the meridian, not the interior of the Three Yin channels. Note: Taiyang belongs to Yang and is at the exterior. Even if deep-tight or deep-slippery pulses appear, they cannot be named as Interior or Yin.)
Shuizhi (Leech, Hirudo nipponica - 30 pieces, fried black in Pig Fat [Zhu Zhi])
Mengchong (Dragonfly Larva, Odonata larvae - 30 pieces, remove head, feet, and wings)
Taoren (Peach Kernel, Persicae Semen - 20 seeds, remove skin and tips, grind)
Dahuang (Rhubarb Root, Radix et Rhizoma Rhei - 4 liang, soaked in wine)
This formula acts on the Foot-Taiyang Bladder Channel. Cheng Wuji stated: Bitter flavors move into the Blood level, salty flavors infiltrate the Blood. The bitter and salty properties of Mengchong and Shuizhi eliminate Blood Stasis accumulation; sweet flavors moderate tension, and bitter flavors drain heat. The sweet and bitter properties of Taoren and Dahuang descend and drain bound heat. (Cheng Jiaoqian stated: Exterior syndrome persists, pulse is faint and deep; this presents exterior symptoms without exterior pulse characteristics, indicating heat in the Lower Jiao. It cannot be dispersed by Guizhi Tang (Cinnamon Twig Decoction) nor attacked by Tao Ren Cheng Qi Tang (Peach Kernel and Magnolia Bark Decoction). Because heat binding in the Bladder differs from stasis-heat in the interior, the pathogen has varying depths of invasion. Therefore, the attack by Tao Ren Cheng Qi Tang and Didang Tang varies in speed and intensity.)
The original formula reduces Shuizhi by 10 pieces, and Mengchong and Taoren each by 5 pieces. These are divided into four pills. Each pill is decocted in water and taken orally. This is named Didang Wan (Didang Pill): It treats the same disease but in cases lacking symptoms of severe forgetfulness or mania. (Shuizhi is the leech, salty and cold, slightly toxic. It is an insect that feeds on blood, capable of unifying blood clots in the Liver Channel. It is extremely difficult to kill; even when roasted and powdered, it revives upon contact with water. If ingested alive, it may breed and cause harm; drinking mud-water can detoxify it. Mengchong is the horsefly/mosquito-like insect; since it feeds on blood, it is used to treat blood disorders. Both medicines are potent and dangerous, rarely used by common practitioners, hence the formulation of Dai Didang Tang (Substitute Didang Decoction). Wu Hegao stated: Ancients used horseflies and leeches to treat blood accumulations because they are adept at sucking blood. Tian Shu Shi (rat droppings, which eat mosquitoes) might also treat blood accumulations. Materia Medica states it expels dead fetuses...)
Appendix: Dai Didang Wan (Substitute Didang Pill):
Dahuang (Rhubarb Root, Radix et Rhizoma Rhei - 4 liang)
Shengdi (Rehmannia Root, Rehmanniae Radix)
Guiwei (Cassia Twig, Cinnamomi Ramulus - specifically the tail end)
Taoren (Peach Kernel, Persicae Semen)
Chuanshanjia (Pangolin Scale, Manis Squama)
Xuanmingfen (Mirabilite, Natrii Sulfas - 1 liang each)
Guixin (Cinnamon Heart, Cinnamomi Cortex - 3 qian)
Prepared as Honey Pills. (Taoren, Guiwei, and Shengdi moisten and unblock; Guixin warms and activates blood flow; Dahuang and Xuanmingfen use bitter-cold and salty-cold properties to push down and purge stagnation; Chuanshanjia is added to guide the medicine to the site of pathology...)