Mai Men Dong Tang (Ophiopogon Decoction) mài mén dōng tāng · 麦门冬汤

Safety. This is a Han-dynasty formula from the Jingui Yaolüe, and it is worth reading as a composition rather than as a list of ingredients: a large amount of the moistening tuber is paired with a much smaller amount of the drying, descending 半夏, and the classical commentary explains that pairing directly - the small acrid, drying component is what keeps the large sweet, moistening one from simply sitting in the stomach. That is a real piece of traditional formula logic and it is one of the passages usually cited to explain why 半夏 appears in a formula whose stated purpose is moistening. - The presenting problems it was written for are chronic cough with scanty sputum and shortness of breath, and vomiting or nausea with a dry mouth. Both of those need the modern differential stated alongside. Chronic cough and breathlessness belong to a list that includes COPD, asthma, interstitial lung disease, bronchiectasis, tuberculosis, heart failure and lung cancer; the traditional category 肺痿, 'lung atrophy', was not arrived at by any method that could separate those from one another. Difficulty swallowing, or vomiting that is progressive, or vomiting with weight loss, needs endoscopy, because oesophageal stricture and oesophageal cancer present exactly that way and treating reflux-type symptoms as a yin-depletion pattern is a documented way of reaching a diagnosis later. - 半夏 is the ingredient with real toxicology. Raw pinellia contains calcium oxalate raphides and a lectin, and chewing it causes immediate burning and swelling of the mouth and throat that can threaten the airway; only processed material belongs in a preparation, and the classical rule places it against the aconite group. - 人参 has a documented interaction with warfarin, can cause insomnia and blood pressure changes, and falls under the incompatibility rule against 藜芦. - 甘草, licorice, in sustained amounts produces a mineralocorticoid-like syndrome - sodium and water retention, potassium loss, raised blood pressure - and interacts with digoxin, diuretics, corticosteroids and drugs that prolong the QT interval; people with hypertension, kidney or heart disease are the group most affected. - 麦冬 is ophiopogon tuber, and the name covers more than one article: 麦冬 proper and 山麦冬 (Liriope) are not identical. - 粳米 is polished rice, so the formula is gluten-free; 大枣 is high in sugar, which matters for people managing blood glucose. - Whether this formula changes the outcome of any of the conditions above has not been established by well-conducted controlled trials; it is unproven. - Quantities are for a licensed practitioner to decide, and are deliberately not listed here.