Xiaobanxia Decoction for Downbearing Counterflow and Stopping Vomiting

Xiaobanxia Decoction comes from Jingui Yaolue (Essentials from the Golden Cabinet). It uses only two herbs: Banxia (Pinelliae Rhizoma) 1 sheng (modern use: 15 g), fresh ginger 0.5 jin (modern use: 24 g). These are boiled in 7 sheng of water down to 1.5 sheng, taken warm in two divided doses (modern usage: decoct twice, take warm in two divided doses).

There are three passages in Jingui Yaolue involving Xiaobanxia Decoction: 1. "Vomiting patients are normally thirsty; thirst indicates the condition is about to resolve. Now, on the contrary, there is no thirst—this is because there is branch-rheum below the heart; Xiaobanxia Decoction governs it" (Tanshin Souke Bing Maijing Bingzhi, Ch. 12); 2. "In jaundice disease, the urine color is unchanged, there is a desire for spontaneous diarrhea, abdominal fullness and panting; heat must not be expelled, for expelling heat will surely cause hiccup. In those with hiccup, Xiaobanxia Decoction governs it" (Huangdan Bing Maijing Bingzhi, Ch. 15); 3. "For all vomiting where food cannot descend, Xiaobanxia Decoction governs it" (Ouye Xiali Bing Maijing Bingzhi, Ch. 17).

In these three passages, the main indication of Xiaobanxia Decoction is always vomiting and regurgitation. In the first, "vomiting patients" are those who vomit; in the second, "hiccup" also means vomiting; and the third is also vomiting.

Xiaobanxia Decoction also has an augmented formula, "Xiaobanxia Plus Fuling Decoction," which also comes from Jingui Yaolue. This formula is Xiaobanxia Decoction plus Fuling (Poria) 3 liang (modern use: 9 g). There are two passages on Xiaobanxia Plus Fuling Decoction: 1. "Sudden vomiting, fullness below the heart, water between the diaphragm, dizziness and palpitations—Xiaobanxia Plus Fuling Decoction governs it" (Tanshin Souke Bing Maijing Bingzhi, Ch. 12); 2. "First thirst, then vomiting, is due to water stagnating below the heart; this belongs to rheum patients—Xiaobanxia Plus Fuling Decoction governs it" (Tanshin Souke Bing Maijing Bingzhi, Ch. 12).

Fuling promotes urination and percolates dampness. Xiaobanxia Plus Fuling Decoction also treats vomiting, but the vomiting patients it treats have the symptom of retained water below the heart or between the diaphragm, so adding Fuling to promote urination and percolate dampness better resolves the patient's problem. The later Erchen Decoction was developed by augmenting Xiaobanxia Decoction.

Banxia is a very warm and drying Chinese herb, with the actions of drying dampness and resolving phlegm, downbearing counterflow and stopping vomiting, and dissipating fullness and nodules. Fresh ginger is pungent and warm, with the actions of releasing the exterior and dispelling cold, warming the middle and stopping vomiting, and warming the lung to stop cough. Thus Xiaobanxia Decoction warms and resolves cold-phlegm and downbears counterflow to stop vomiting. Both Banxia and fresh ginger are pungent-warm herbs, so patients with vomiting caused by heat syndrome should use it with caution.

Patients with heat syndrome have symptoms such as dry mouth and tongue, difficult urination, and constipation. Xiaobanxia Decoction in Jingui Yaolue is suitable for patients who vomit but are not thirsty, and those with jaundice but clear-colored and freely flowing urine; all these indicate that the patient has no heat syndrome.

Xiaobanxia Plus Fuling Decoction involves "thirst." This thirst is because water-rheum is retained below the heart (i.e., the epigastrium), the spleen qi fails to rise, and fluids cannot reach upward to the throat, causing the symptom of thirst. Moreover, it is thirst first, then vomiting; using Xiaobanxia Fuling Decoction to restore the ascending and descending functions of the spleen and stomach makes the fluids harmonize of themselves, and the thirst resolves without directly treating it.

Although Xiaobanxia Decoction is simple, it is very useful for resolving symptoms such as vomiting and vertigo. In clinical practice, nausea, vomiting, and vertigo of various causes, as long as they match the formula-pattern of Xiaobanxia Decoction or Xiaobanxia Plus Fuling Decoction, can be resolved with either. The author often uses these two formulas to treat nausea and vomiting in chemotherapy patients, and also augments them to treat pleural and ascitic effusion, with some efficacy.