Chan Su蟾酥
Bufonis Venenum · Toad Venom · Dried Toad Secretion
Overview
Chan Su is the white secretion squeezed from the parotoid and skin glands of the toads Bufo bufo gargarizans and Duttaphrynus melanostictus, dried into hard cakes or discs. Acrid, warm and toxic, entering the Heart channel alone, it resolves toxin and stops pain in minute amounts, and rouses a spirit clouded by a sudden turbid attack — the action that puts it beside the orifice-opening herbs. The textbook classes it chiefly with the toxic, largely external-use drugs, and it is grouped here for that action; either way it is a poison first. Its bufadienolides act on the heart in the same manner as digitalis, so the daily ceiling is measured in hundredths of a gram, it is never decocted, and it is dispensed only inside manufactured preparations.
Nature & Flavor
Acrid · Warm · ToxicChannels
HeartTypical Dosage
0.015–0.03 gActions
3 core actions
- Resolves toxin, disperses swellingBoils, deep abscesses and stubborn sores, swollen painful throat and toothache — in milligram amounts inside pills such as Liu Shen Wan and Chan Su Wan, and topically in plasters and dusting powders.
- Stops pain, numbs the surfaceApplied locally it produces marked numbness, which classical practice used for toothache and painful sores. The same property is the reason it must be kept clear of the eyes and of any mucous membrane.
- Opens the orifices, rouses the spiritThe presentation — a sudden turbid attack with cramping abdominal pain, vomiting and diarrhoea running on to clouded consciousness. This is the classical indication that places it in the orifice-opening chapter.
In Formulas
Formulas containing Chan Su
No published formula lists this herb yet — the library is growing.
Indications & Clinical Uses
- Boils, deep abscesses and stubborn sores (topical, and in prepared pills)
- Swollen painful throat and toothache
- Local pain requiring surface numbing (topical)
- Sudden turbid attack with abdominal pain, vomiting, diarrhoea and clouding of consciousness
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
Toxic — handled as a poison. Chan Su contains bufadienolides (bufalin, cinobufagin, resibufogenin), which act on the heart in the same way as digitalis. The pharmacopoeia ceiling is 0.03 g in a day and it must not be exceeded on any pretext. Early poisoning gives numb, tingling lips and tongue, nausea, vomiting, abdominal pain and dizziness; it progresses to a slow or irregular pulse, atrioventricular block, ventricular arrhythmia, falling blood pressure and cardiac arrest. Deaths are on record from swallowing topical 'aphrodisiac' products containing toad venom and from eating toads or toad soup. Suspected poisoning is a medical emergency — go to hospital, and take the packaging.
Never let it reach the eyes. Powder or fresh secretion in the eye causes immediate severe pain, redness and swelling, corneal damage and possible loss of sight. Anyone handling the raw material must wash their hands thoroughly before touching their face, and must not rub the eyes while working with it. If it does get in, irrigate with plenty of clean water at once and seek ophthalmic care.
Route and form. Never decocted. Used processed and finely powdered inside prepared pills, or externally in small amounts; it is not dispensed loose. Do not apply it to large areas, to broken skin or to open wounds, where enough can be absorbed to cause systemic poisoning.
Combinations and comorbidity. Do not use with digoxin or other cardiac glycosides — the cardiac effects are additive, and toad venom also interferes with digoxin immunoassays so measured blood levels can mislead. Avoid in existing heart disease and arrhythmia, and in children and the frail elderly. Injectable and oral hospital preparations derived from toad venom are specialist pharmaceutical products and fall outside herbal prescribing. Store locked away from children.
Contraindicated in pregnancy: Do not use in pregnancy. The pharmacopoeia marks it 'use with caution', but given its cardiotoxicity and its strongly moving, toxic nature it should be treated as contraindicated throughout pregnancy, patent pills containing it included. Avoid while breastfeeding as well.
For licensed practitioners’ reference only
References
- Yao Xing Lun《药性论》(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》.
4. 《中药大辞典》.
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.