气寒，味苦。味浓气薄，阴中阳也，升也。无毒。
入手少阴经。
《象》云∶泻心火，除脾胃中湿热，治烦躁恶心，郁热在中焦，兀兀欲吐，心下痞满必用药
也。仲景治九种心下痞，
五等泻心汤皆用之
《心》云∶泻心经之火，眼暴赤肿，及诸疮，须用之。苦寒者主阳有余，苦以除之。安蛔，
通寒格，疗下焦虚，坚
肾。
《珍》云∶酒炒上行，酒浸行上头。
《本草》云∶主热气，目痛 伤泣出，明目。肠 腹痛下痢，妇人阴中肿痛。五脏冷热
，久下泄 脓血，止消渴大惊，除水利骨，调胃浓肠，益胆，疗口疮。久服令人不忘。
《液》云∶入手少阴，苦燥，故入心，火就燥也。然泻心其实泻脾也，为子能令母实，
实则泻其子。治血，防风为上使，黄连为中使，地榆为下使。
海藏祖方，令终身不发斑疮，煎黄连一口，儿生未出声时，灌之，大应。已出声灌之，
斑虽发，亦轻。古方以黄连为治痢之最。
《衍义》云∶治痢有微血，不可执以黄连。为苦燥剂，虚者多致危困，实者宜用之。
《本草》又云∶龙骨、理石、黄芩为之使，恶菊花、芫花、玄参、白藓皮。畏款冬花。
胜乌头，解巴豆毒。
气寒。味苦，大寒。味极浓，阴也，降也。无毒。
入手足阳明经。酒浸，入太阳
《象》云∶性走而不守，泻诸实热不通，下大便，涤荡肠胃间热，专治不大便。
《心》云∶涤荡实热。
《珍》云∶热淫于内，以苦泄之。酒浸入太阳经，酒洗入阳明经，余经不用酒。
《本草》云∶主下瘀血，血闭寒热，破症瘕积聚，留饮宿食，荡涤肠胃，推陈致新，
通利水谷，调中化食，安和五脏。平胃下气，除痰实，肠间结热，心腹胀满，女子寒血闭，
胀，小腹痛，诸老血留结。
《液》云∶味苦、寒，阴中之阴药。泄漏，推陈致新，去陈垢而安五脏，谓如戡定祸乱
以致太平无异，所以有将军之名。入手足阳明，以酒引之，上至高巅；以舟楫载之，胸中可
浮；以苦泄之，性峻至于下。以酒将之，可行至高之分，若物在巅，人迹不及，必射以取之
也。故太阳阳明、正阳阳明承气汤中俱用酒浸，惟少阳阳明为下经，故小承气汤中不用酒浸
也。杂方有生用者，有面裹蒸熟者，其制不等。
《衍义》云∶损益前书已具。仲景治心气不足，吐血衄血，泻心汤用大黄、黄芩、黄连
。或曰∶心气既不足矣，而不用补心汤，更用泻心汤，何也？答曰∶若心气独不足，则须当
不吐衄也，此乃邪热因心气不足而客之，故令吐衄。以苦泄其热，就以苦补其心，盖一举而
两得之。有是证者，用之无不效，惟在量其虚实而已。
《本草》又云∶恶干漆。
黄连：
药性气寒，味苦。气味浓烈而轻清，属于阴中有阳，具有升散之性。无毒。
归入手少阴心经。
《本草发挥》（李东垣）说：能泻心火，清除脾胃中的湿热，治疗烦躁恶心、中焦郁热、头晕欲吐、心下痞满，是必用的药物。张仲景治疗九种心下痞证，五种泻心汤都使用它。
《用药法象》（王好古）说：能泻心经之火，治疗眼睛突然红肿以及各种疮疡，必须使用它。苦寒的药物主要治疗阳气有余，用苦味来消除它。能安蛔虫，通治寒格（上下不通），治疗下焦虚损，坚固肾气。
《珍珠囊》（张元素）说：酒炒后药性上行，酒浸后能行于头部。
《神农本草经》说：主治热气，目痛流泪，明目。治疗肠鸣腹痛、下痢，妇人阴部肿痛。五脏冷热不调，长期腹泻脓血，止消渴和大惊，利水强骨，调和胃肠，益胆，治疗口疮。长期服用使人不忘事。
《汤液本草》（王好古）说：归入手少阴心经，苦能燥湿，所以入心，因为火性就燥。然而泻心实际上是泻脾，因为子能令母实，实则泻其子。治疗血证时，防风为引经上使，黄连为中使，地榆为下使。
海藏（张元素）的祖传方剂，让人终身不发斑疮，煎煮一口黄连，在婴儿出生尚未出声时灌服，效果显著。如果已经出声后再灌服，即使发斑，症状也会较轻。古方认为黄连是治疗痢疾的最佳药物。
《本草衍义》（寇宗奭）说：治疗痢疾若有微血，不可固执只用黄连。因为它是苦燥之剂，虚证患者多会导致危重困顿，实证患者才适宜使用。
《神农本草经》又说：龙骨、理石、黄芩为其佐使药，畏恶菊花、芫花、玄参、白鲜皮。畏惧款冬花。能克制乌头，解除巴豆毒。
大黄：
药性气寒。味苦，大寒。气味极浓烈，属阴，具有沉降之性。无毒。
归入手足阳明经。酒浸则入太阳经。
《本草发挥》（李东垣）说：药性走窜而不守静，泻除各种实热阻滞，通导大便，涤荡肠胃间的积热，专门治疗大便不通。
《用药法象》（王好古）说：涤荡实热。
《珍珠囊》（张元素）说：热邪淫溢于内，用苦味泄之。酒浸则入太阳经，酒洗则入阳明经，其他经络不用酒制。
《神农本草经》说：主治下瘀血，血闭寒热，破除癥瘕积聚，留饮宿食，荡涤肠胃，推陈致新，通利水谷，调和脾胃消化食物，安宁五脏。平胃下气，除去痰实，肠间结热，心腹胀满，女子寒凝血闭，胀满，小腹痛，各种陈旧性瘀血留结。
《汤液本草》（王好古）说：味苦、寒，是阴中之阴的药。泄漏（指通下），推陈致新，去除陈垢而安宁五脏，就像平定祸乱以致太平一样，所以有“将军”的名号。归入手足阳明经，用酒引导，可上达至高之处；像舟楫一样载药上浮，可在胸中浮动；用苦味泄降，药性峻猛直达下部。用酒引领，可以行至最高部位，如同物体在山顶，人的足迹达不到，必须用箭射取一样。所以太阳阳明、正阳明承气汤中都使用酒浸大黄，只有少阳阳明属于下经，所以小承气汤中不使用酒浸大黄。杂方中有生用的，有用面粉包裹蒸熟的，炮制方法不等。
《本草衍义》（寇宗奭）说：对前书的损益已具备。张仲景治疗心气不足，吐血衄血，泻心汤中使用大黄、黄芩、黄连。有人说：心气既然不足，为何不用补心汤，反而用泻心汤？回答说：如果仅仅是心气独缺不足，就不应该出现吐血衄血了，这是邪热因心气不足而客居于心，所以导致吐血衄血。用苦味泄其热，也就以苦味补其心，这是一举两得。有这种证候的人，使用没有不有效的，只在于衡量其虚实程度而已。
《神农本草经》又说：畏恶干漆。
Coptidis Rhizoma (Huanglian, 黄连):
The qi is cold, the taste is bitter. The taste is strong and the qi is thin, belonging to yin containing yang, with an ascending nature. It is non-toxic.
It enters the Hand-Shaoyin Heart Meridian.
Li Dongyuan states: It drains Heart Fire, removes damp-heat in the Spleen and Stomach, treats irritability, nausea, stagnant heat in the Middle Jiao, dizziness with a desire to vomit, and fullness below the heart. It is an essential medicine for these conditions. Zhang Zhongjing uses it in all five formulas of Xiexin Tang (Drain the Epigastrium Decoction) to treat nine types of epigastric fullness.
Wang Haogu states: It drains the fire of the Heart Meridian, treats sudden redness and swelling of the eyes, and various sores; it must be used. Bitter-cold substances primarily address excess Yang, using bitterness to eliminate it. It calms roundworms, resolves cold obstruction (Han Ge), treats deficiency of the Lower Jiao, and consolidates Kidney Qi.
Zhang Yuansu states: Stir-fried with wine, its action ascends; soaked in wine, it travels to the head.
Shennong Bencao Jing states: It governs hot pathogens, eye pain with tearing, brightens the eyes. It treats abdominal pain with borborygmus, dysentery, and swelling and pain in the female genitalia. For cold and heat disorders of the Five Zang organs, chronic diarrhea with pus and blood, it stops polydipsia and great fright, promotes water metabolism and strengthens bones, harmonizes the Stomach and intestines, benefits the Gallbladder, and treats mouth ulcers. Long-term use prevents forgetfulness.
Wang Haogu states: It enters the Hand-Shaoyin Heart Meridian. Bitterness dries dampness, thus entering the Heart, as Fire tends towards dryness. However, draining the Heart actually drains the Spleen, because the Son can cause the Mother to be full; when full, drain the Son. When treating blood disorders, Fangfeng (Saposhnikoviae Radix) acts as the upper guiding herb, Huanglian as the middle guiding herb, and Diyuyu (Sanguisorbae Radix) as the lower guiding herb.
Zhang Yuansu's ancestral prescription prevents variola (smallpox/varioliform eruptions) for life: decoct one mouthful of Huanglian and administer it to the infant before it cries upon birth; this is highly effective. If administered after crying, even if eruptions occur, they will be mild. Ancient formulas regard Huanglian as the best medicine for treating dysentery.
Kou Zongshi states: In treating dysentery with slight bleeding, one should not rigidly rely on Huanglian. As a bitter-drying agent, it often leads to critical distress in deficient patients, but is suitable for excess patients.
Shennong Bencao Jing further states: Longgu (Fossil Bones), Lishi (Calcitum), and Huangqin (Scutellariae Radix) act as its assistants. It is incompatible with Juhua (Chrysanthemi Flos), Yuanhua (Genkwa Flos), Xuanshen (Scrophulariae Radix), and Baixianpi (Dictamni Cortex). It is inhibited by Kuandonghua (Adenophorae Radix). It overcomes Aconitum and resolves the toxicity of Ban Dou (Crotonis Fructus).
Rhei Radix et Rhizoma (Dahuang, 大黄):
The qi is cold. The taste is bitter, extremely cold. The taste is very strong, belonging to Yin, with a descending nature. It is non-toxic.
It enters the Foot-Yangming Stomach Meridian and Hand-Yangming Large Intestine Meridian. Wine-soaked, it enters the Taiyang Bladder Meridian.
Li Dongyuan states: Its nature moves freely and does not stay static; it drains various excess heat obstructions, promotes bowel movements, cleanses heat from the intestines and stomach, and specifically treats constipation.
Wang Haogu states: Cleanses excess heat.
Zhang Yuansu states: When heat pathogens overflow internally, use bitterness to drain them. Wine-soaked, it enters the Taiyang Meridian; wine-washed, it enters the Yangming Meridian; other meridians do not require wine processing.
Shennong Bencao Jing states: It governs subcutaneous blood stasis, blood closure with chills and fever, breaks masses and accumulations, residual fluid retention and old food stagnation, purges the intestines and stomach, pushes out the old and brings forth the new, promotes the passage of water and grain, harmonizes the center to transform food, and pacifies the Five Zang organs. It levels the Stomach and directs Qi downward, eliminates phlegm and excess, clears inter-intestinal binding heat, relieves epigastric and abdominal fullness, treats cold blood closure in women, distension, lower abdominal pain, and various old blood stasis bindings.
Wang Haogu states: Bitter and cold, it is a Yin-within-Yin medicine. It leaks (purges), pushes out the old and brings forth the new, removes filth to pacify the Five Zang organs. This is akin to quelling chaos to achieve peace, hence its name "General". Entering the Foot-Yangming and Hand-Yangming meridians, guided by wine, it reaches the highest peak; like a boat carrying cargo, it floats in the chest; drained by bitterness, its nature is峻猛 (harsh/potent) reaching downwards. Guided by wine, it can travel to the highest parts, just as objects on a peak are beyond human reach and must be shot down with arrows. Therefore, in Taiyang-Yangming and Zhengyang-Yangming Chengqi Tang (Harmonizing the Yang Decoctions), wine-soaked Dahuang is used. Only Shaoyang-Yangming belongs to the lower meridian, so Xiaochengqi Tang (Minor Harmonizing the Yang Decoction) does not use wine-soaked Dahuang. Miscellaneous formulas use either raw or flour-steamed forms, with varying preparations.
Kou Zongshi states: The modifications of previous texts are already detailed. Zhang Zhongjing treats Heart Qi deficiency with hematemesis and epistaxis using Xiexin Tang, which contains Dahuang, Huangqin, and Huanglian. Some ask: Since Heart Qi is deficient, why not use a Heart-tonifying formula, but rather a draining formula? The answer is: If Heart Qi were solely deficient, there would be no hematemesis or epistaxis. Here, pathogenic heat lodges due to Heart Qi deficiency, causing bleeding. Using bitterness to drain the heat simultaneously tonifies the Heart with bitterness, achieving two goals with one move. For those with this syndrome, it is invariably effective, provided one assesses the deficiency or excess.
Shennong Bencao Jing further states: It is incompatible with Ganqi (Gambir Resina).