Wutou Tang (Aconite Decoction) wū tóu tāng · 乌头汤

Safety. Jingui Yaolüe places Wutou Tang in the chapter on wind-stroke and joint disease, for 历节: joints that are painful and will not flex or extend. Five ingredients, and the first one carries the safety burden for the whole batch: this is the only formula in this library whose leading herb is Aconitum. The classical text does not treat that lightly. It instructs that the aconite be cut up and simmered with honey, that the liquid be reduced, and that the aconite pieces be discarded before the remaining four herbs are decocted and added. Modern chemistry explains why that instruction exists. The diester-type alkaloids in raw aconite — aconitine above all — are cardiotoxic and neurotoxic, and they hydrolyse under prolonged moist heat into far less toxic monoester alkaloids. Aconitine poisoning has no specific antidote. Reported cases include ventricular arrhythmia, profound numbness and paraesthesia of mouth and limbs, vomiting, and death, arising both from insufficiently cooked decoctions and from homemade medicinal wines and powders. Several countries restrict these plants outright. Nothing in this entry should be read as instruction on how to prepare one. The second ingredient is equally non-inert. Ephedra herb is the source of ephedrine, a sympathomimetic amine with well-defined cardiovascular effects; it has a documented history of serious adverse events in weight-loss and sports supplements and is banned or restricted in several jurisdictions. A formula pairing aconite and ephedra puts two agents acting on the heart in the same bowl. Of the remaining three, peony root is comparatively unremarkable; astragalus carries a genuine species-confusion problem, since some Astragalus species contain the neurotoxic alkaloid swainsonine; and liquorice carries the glycyrrhizin problem described elsewhere in this library — pseudoaldosteronism with potassium loss and raised blood pressure, dangerous alongside diuretics, digoxin or anthraquinone laxatives. What 历节 means today is the part readers most often skip. "Joints too painful to move" is not a diagnosis; it is a presentation with a short mandatory list. Septic arthritis destroys cartilage within days and is excluded by aspirating the joint, not by looking at it. Gout and calcium pyrophosphate deposition both mimic it. So do fracture, deep vein thrombosis, cellulitis adjacent to a joint, and rheumatoid arthritis — probably closest to what the classical word covers, and now managed with disease-modifying drugs. Reaching "wind and dampness" before that list has been excluded puts a traditional label in front of a condition with a specific modern management. Chinese-language literature reports clinical observations of Wutou Tang in rheumatoid arthritis and knee osteoarthritis, and a Kampo counterpart called Wutō-tō exists in Japan. The studies are small, mostly open-label, rarely blinded. This library records that research exists; it does not record that efficacy has been established. Pregnancy is an absolute exclusion for this formula.