Ma Xing Shi Gan Tang (Ephedra, Apricot Kernel, Gypsum and Licorice Decoction) má xìng shí gān tāng · 麻杏石甘汤

Safety. The Shanghan Lun line is short and it reads like a correction rather than a discovery: after sweating has been induced, Gui Zhi Tang must not be given again; where there is sweating and panting and no great heat, Ma Xing Shi Gan Tang may be given. There is a parallel line for the case after purgation. What everybody learns from this pair of lines is the edit itself. Take Ma Huang Tang and exchange its cinnamon twig for gypsum, and a formula built to make a person sweat becomes one built to clear heat from the lung without driving sweat. Almost the entire teaching apparatus of Chinese formula study - chief, deputy, assistant, envoy, and the idea that one substitution redirects the whole - can be taught from this single swap, and it usually is. The clause rendered above as no great heat has been argued about for a long time, and this knowledge base is not going to pretend otherwise. Readings take it variously as indicating that the heat is internal rather than at the surface, or as contrasting with the great heat of the yang brightness stage. The argument is recorded rather than resolved, because substituting a confident reading for an old disagreement is precisely the thing this site declines to do. Then the two notes that determine how this entry has to be written, because two of these four materials are among the most heavily regulated herbal items in the English-speaking world and both got that way through bodies rather than arguments. Ephedra is the source of the ephedrine alkaloids. They are sympathomimetic: they raise blood pressure and heart rate, and the adverse event reports attached to them include myocardial infarction, stroke, serious ventricular arrhythmias, sudden death, seizures and psychiatric reactions. In 2004 the United States Food and Drug Administration declared dietary supplements containing ephedrine alkaloids adulterated; litigation narrowed some edges of that rule, and the practical position since is that such supplements are not lawfully marketed in the United States, with controls in other countries besides. Ephedrine is also prohibited in sport by the World Anti-Doping Agency. There is an extra point that belongs specifically to this formula rather than to the herb: the person being treated is short of breath, and breathlessness has a differential that includes heart failure, pulmonary embolism, arrhythmia and anaphylaxis, in all of which a sympathomimetic is the wrong class of drug. Many such patients are already taking beta-blockers, antihypertensives, decongestants, stimulants, theophylline or monoamine oxidase inhibitors, or have hyperthyroidism, glaucoma or prostatic enlargement. And it is worth knowing that ephedrine is also a regulated precursor in the synthesis of methamphetamine, which is why this herb carries supply controls in several countries. That last fact has nothing to do with anyone taking this formula and everything to do with what the plant happens to contain. Bitter apricot kernel contains amygdalin, and on hydrolysis amygdalin releases cyanide. Poisoning has been reported repeatedly and disproportionately in children and after unprocessed kernels, which is why Chinese materia medica classifies the item as slightly toxic and requires processing, and why the sweet apricot kernel sold as food is not the same thing. The laetrile story belongs here too, because it is the reason regulators are firm rather than merely cautious: the claim that amygdalin selectively destroys cancer was tested and not supported, while cyanide poisoning from it is well documented. No demonstrated benefit plus a real and severe harm is about as unfavourable as a risk-benefit ratio gets. The other two are milder but not inert. Liquorice brings the glycyrrhizin problem - enough of it over long enough produces the picture of apparent mineralocorticoid excess, with fluid retention, raised blood pressure and low potassium. Gypsum is a mineral, and mineral drugs carry a documented risk of heavy metal contamination, so for this one the source of the material is not a footnote. Clinically, the presentation this formula addresses is the presentation emergency medicine most wants to see early: cough, breathlessness, fever that will not settle. Red flags move it out of the clinic and into an emergency department: chest pain, breathlessness at rest or inability to speak in full sentences, coughing up blood, blue lips, a swollen painful calf with sudden pleuritic pain, drowsiness or confusion. In children the list is different and faster - bronchiolitis, croup, inhaled foreign body, epiglottitis - and it is measured in hours. In China this formula is used very widely today for pneumonia, bronchitis, asthma and COPD in children and adults, and there is a large Chinese-language clinical literature around it; the systematic reviews that have appraised those trials generally conclude that the evidence is low-certainty, chiefly because of risk of bias and heterogeneous outcomes. Widely used, plausibly useful, not established is the honest summary, and it is what this entry will say. One sentence is offered without any hedge at all: anyone who is breathless at rest, or has chest pain, or is coughing up blood, needs assessment now, and no herbal preparation changes that.