Source 出处 · Yixue Xinwu · Doses are not given here: they are set by a licensed practitioner for the individual.
Safety. Bei Mu Gua Lou San is recorded in Yixue Xinwu, Cheng Guopeng's eighteenth-century primer, a book written to make the tradition teachable rather than to add to it. Six herbs: bei mu, gua lou, tian hua fen, ju hong, fu ling and jie geng.
The pattern it is written for is called dry phlegm, and the name is the description: sputum that is scanty, sticky and hard to bring up, with a dry mouth and throat. A reader who has only met the damp-phlegm formulas in this library should notice what is missing here — no drying herb, no acrid dispersing herb, nothing that drains. The formula moistens and loosens. Bei mu and gua lou do the main work; tian hua fen generates fluid; ju hong moves qi on the classical argument that phlegm clears once qi moves; fu ling leaches; jie geng is the carrier that directs upward and opens the lung. It is the mildest formula in this batch, and its mildness is the reason it is often the one people reach for at home.
Two naming problems must be stated, because both cause real confusion in shops. First, bei mu is more than one herb: chuan bei mu and zhe bei mu have separate Pharmacopoeia entries, are described differently, and are not interchangeable. Second, gua lou and tian hua fen are the fruit and the root of the same plant, and this formula deliberately uses both; they are two herbs, not one herb twice.
A modern reader should know what a persistent dry cough can be. Cough lasting more than eight weeks is chronic cough, and the common causes are upper airway cough syndrome, cough-variant asthma, gastro-oesophageal reflux and ACE inhibitor therapy. Dry mouth and eyes with a dry cough suggests Sjögren's syndrome; thirst with polyuria suggests diabetes; and cough with blood, weight loss, night sweats or fever points at tuberculosis, bronchiectasis and lung cancer, all of which occur commonly in the populations where this formula is used. Pulse and tongue examination cannot separate any of these.
Safety. Bei mu appears in the classical list of herbs held to be antagonistic to the aconite group. Fritillaria alkaloids have their own toxicity profile, distinct from the sodium-channel cardiotoxicity of aconite, and large exposures have been associated with central nervous and respiratory depression; that is reported as a toxicological contrast, not as a reason to think the herb is dangerous in dispensing practice. Tian hua fen is the more serious caution: trichosanthin, a protein isolated from this root, was studied as an abortifacient and is associated with severe hypersensitivity reactions, and the herb is contraindicated in pregnancy. Jie geng contains saponins that are locally irritant and cause nausea in large amounts. Ju hong is citrus peel, and hua ju hong from pomelo peel is a different substance sold under a similar name. This library does not claim this formula resolves phlegm, stops cough or treats any specific disease, and it offers no opinion on the household practice of stewing chuan bei mu with pear.
贝母瓜蒌散著录于程国彭《医学心悟》—— 一部为了让这套传统「可教」而写的十八世纪入门书，而不是为了给它添新内容。六味：贝母、瓜蒌、天花粉、橘红、茯苓、桔梗。
它所主的证叫**燥痰**，方名即描述：痰少而黏、咯吐不利，伴口干咽燥。只读过本库燥湿化痰类方剂的读者应当注意这里**缺什么**：没有一味燥湿药，没有一味辛散药，没有一味攻逐的药。这首方是润与开。贝母与瓜蒌做主力，天花粉生津，橘红行气（依据仍是「气顺则痰消」），茯苓渗湿，桔梗是载药上行、开宣肺气的一味。它是本批四首里最温和的一首，而这份温和正是人们常在家里自行用它的原因。
两个命名问题必须说清，因为在药店里两者都造成过真实混乱。其一，**贝母不止一味**：川贝母与浙贝母在药典分列两条，传统描述不同，不可互代。其二，**瓜蒌与天花粉是同一植物的果实与根**，而本方有意两味同用；它们是两味药，不是同一味用了两次。
今天的读者需要知道持续性干咳可能是什么。咳嗽超过八周即为慢性咳嗽，常见原因是上气道咳嗽综合征、咳嗽变异性哮喘、胃食管反流与 ACEI 类药物。口干眼干伴干咳提示干燥综合征；口渴多饮伴多尿提示糖尿病；而咳嗽伴咯血、体重下降、盗汗或发热，指向结核、支气管扩张与肺癌 —— 这些在使用本方的人群里都不罕见。脉与舌不能把它们分开。
安全上：贝母在古典「反乌头」之列。**贝母属生物碱的毒性谱与乌头类相反** —— 乌头是钠通道与心脏毒性，贝母则与中枢及呼吸抑制相关（本库把它写成毒理学的对照，而不是说调剂用量的贝母是危险的）。**天花粉是更重的一条**：自该根提得的天花粉蛋白曾被作为引产药研究，并与严重过敏反应相关，且**孕期禁用**。桔梗含皂苷，局部有刺激性，量大致恶心。橘红是柑橘类果皮，另有一种「化橘红」取自柚类果皮，名近而物异。本库不声称本方能化痰、止咳或治疗任何具体疾病，也不评价川贝炖梨这一民间做法。