Source 出处 · Beiji Qianjin Yaofang · Doses are not given here: they are set by a licensed practitioner for the individual.
Safety. Sun Simiao's Beiji Qianjin Yaofang gives this for lung abscess, and the clinical picture it describes is unmistakable and unpleasant: cough bringing up foul-smelling blood-streaked sputum, chest pain, and a febrile state that will not settle. The logic can be stated once and then it is visible - clear the lung and open the passages (the reed stem itself, a hollow aquatic stem, carries a little of that reasoning on its face), drain damp and let pus find its way out (coix seed, wax gourd seed), and move what has congealed (peach kernel).
The honest part is the whole of the safety note. A condition that produces foul purulent sputum is one of the places where classical and modern medicine differ least in how dangerous they think it is and most in what they can do about it. Lung abscess before antibiotics carried a high mortality, and what it corresponds to in a modern clinic is still serious: lung abscess proper, necrotising pneumonia, empyema, bronchiectasis with superinfection, aspiration, post-obstructive pneumonia lying behind a tumour, and tuberculosis presenting with cavitation. These are separated by imaging and by microbiology, not by the character of the sputum. Some need a drain placed, some need months of targeted antimicrobial therapy, and none can be reliably recognised from a description written in the seventh century. Tuberculosis earns its own sentence because it is the one still being transmitted to other people in the household while it is worked out, and because cavitating tuberculosis and lung abscess look very much alike when the only instrument available is a description.
Then the naming problems, which are real and better stated than tidied away. The source text is read as saying melon petal rather than wax gourd seed, and commentators have variously taken it to mean wax gourd seed, another melon seed, or something else altogether; modern dispensing practice settles it as wax gourd seed. Reed stem likewise is today overwhelmingly dispensed as reed rhizome - a different part of a related plant with a different name - which is a substitution most practitioners know about and which a reader is entitled to know too. Peach kernel is a Rosaceae stone seed and therefore carries the cyanogenic glycoside question it shares with bitter apricot kernel, and it is a blood-moving material that the tradition treats as unsuitable in pregnancy. Coix seed carries that same traditional caution about slippery, downward-moving materials in pregnancy, and it is a grass, so gluten is not a concern here. Coix seed oil has in modern China been developed into an injectable preparation used alongside cancer treatment; that concerns a concentrated extract given by another route, and whatever its evidence is, it belongs to a different question from anything in this decoction.
And the closing point, which is the one that matters: this knowledge base cannot tell you whether what is being described is lung abscess, tuberculosis or a tumour, and neither can the formula. Foul-smelling sputum, or blood in the sputum, gets looked at.
孙思邈《备急千金要方》以此方主肺痈，而它描写的临床画面清楚而不体面：咳吐腥臭、带脓带血的痰，胸痛，以及不肯平复的热势。它的理路只要说一遍就能看清——清肺开窍者是苇茎（一根中空的草本水茎，这个形象本身就把那层意思写在脸上），排脓利湿者是薏苡仁与冬瓜仁，推动已凝滞之物者是桃仁。
诚实的部分构成了整则安全提示。一个会咳出腥臭脓痰的病位，恰是古典与现代两头在「危险程度」上判断最一致、而在「能做什么」上差别最大的地方。抗生素之前的肺痈死亡率很高；而它在现代诊所里所对应的，至今仍然严重：肺痈本身、坏死性肺炎、脓胸、支气管扩张合并感染、吸入性病变、肿瘤阻塞后方的阻塞性肺炎，以及表现为空洞的结核。把它们分开的是影像与微生物检查，不是痰的样子。其中有的需要置管引流，有的需要数月的针对性抗微生物治疗，而没有任何一种可以凭七世纪的一段描述可靠地认出来。结核值得单独一句：它是别人还在旁边共处时就能传染的那一种，而且在没有影像手段的时候，空洞性结核与肺痈看起来非常像。
然后是命名问题，那也是真实的，说出来比抹平要好。原文据读作「瓜瓣」，注家或以为冬瓜子、或以为别的瓜子、或以为另有其物；现代调剂习惯把它定为冬瓜仁。苇茎同理——今天绝大多数以芦根入药，那是近缘植物的另一个部位、另一个药名；这是业内共知的代用，读者也有权知道。桃仁是蔷薇科李属的种子，因此带有与苦杏仁相同的氰苷问题，且它活血，传统认为孕期不宜。薏苡仁亦带同一类关于滑利下行之物在孕期慎用的传统告诫；它是禾本科种子，故麸质在这里不是问题。现代中国把薏苡仁油开发成注射剂用于肿瘤治疗的配合，那是浓缩提取物、另一条给药途径，无论证据如何，它属于与本方无关的另一个问题。
最后是那句要紧话：本站无法告诉你正在描述的究竟是肺痈、结核还是肿瘤，此方也不能。痰有腥臭，或痰中有血，就应当去检查。