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Chang Shan常山

Dichroae Radix · Dichroa Root

Herbs that Induce Vomiting 涌吐药《神农本草经》

Overview

The root of Dichroa febrifuga — bitter, acrid, cold and recorded as toxic. It is the lead herb of the emetic chapter: it brings up phlegm lodged in the chest, and it interrupts the fever cycle of malaria. Both effects come from the same alkaloids, and the vomiting is not an unwanted extra but the mechanism itself, which is also why the herb has all but left clinical use. Emesis as a treatment method has been replaced in every acute setting by gastric lavage and activated charcoal, and the antimalarial role by artemisinin. This entry records what the classical materia medica taught; it is not a course of treatment.

Nature & Flavor

Bitter, acrid · Cold · Toxic

Channels

Lung · Heart · Liver

Typical Dosage

4.5–9 g in decoction
常山Photography for this entry is on its way.

Actions

3 core actions

  • Induces vomiting of phlegmPhlegm and undigested food held above the diaphragm, with a stifling fullness in the chest and epigastrium; classically also for phlegm-obstruction seizure and mania. The raw root is the emetic form.
  • Interrupts malarial paroxysmsAlternating chills and fever on a fixed cycle. The classical instruction is to give it roughly two hours before the expected attack, wine-processed so that the patient does not simply vomit the dose.
  • Raw and processed forms differRaw Chang Shan vomits; wine-processed Chang Shan is the tempered form. Substituting one for the other changes what the herb does, and the raw form is never the right choice when emesis is not intended.

In Formulas

Formulas containing Chang Shan

Indications & Clinical Uses

  • Phlegm and food lodged in the chest with stifling fullness (classical emetic use)
    - Phlegm-obstruction seizure and mania (classical)
    - Malarial alternating chills and fever (superseded by modern antimalarials)

Western Medical Keywords

Searchable condition terms

MalariaInduced emesisGastric retention

Contraindications

Cautions

Chang Shan is toxic. It reliably produces nausea, vomiting and abdominal pain, and larger amounts have caused gastrointestinal bleeding, dizziness, palpitations and a fall in blood pressure; the gap between an effective and a harmful amount is narrow. Keep to 5–9 g, stop the moment the intended effect is reached, and never combine it with another emetic. It is unsuitable for weak, elderly, dehydrated or fluid-depleted patients, for anyone with a bleeding tendency or upper gastrointestinal disease, and for children. Deliberate emesis has no place in modern management of poisoning or overdose — that is an emergency-services matter, not a herbal one. If vomiting will not settle, stop the herb, give fluids and seek medical care.

Contraindicated in pregnancy: Contraindicated in pregnancy — the herb is toxic and violent vomiting is itself a risk to the pregnancy.

For licensed practitioners’ reference only

References

  1. Shen Nong Ben Cao Jing《神农本草经》(classical source, public domain).
    2. Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.
    3. 《中华人民共和国药典》.

Professional reference notice. Entries are scholarly references for licensed TCM practitioners and students — not medical advice, and not a recommendation to self-prescribe. Chinese herbal formulas should be used under the guidance of a qualified practitioner. Content is an original editorial compilation by Cura x Cura, cross-checked against the cited references.