Shenzhuo Decoction (Gan Jiang Ling Zhu Tang) for Lower-Limb Edema, Lumbar Muscle Strain, and Senile Bi Pain

Gan Jiang Ling Zhu Tang comes from the *Essential Prescriptions of the Golden Cabinet* (Jinkui Yaolue); in the *Thousand Golden Ducat Formulary* (Qianjin Fang) it is also named "Shenzhuo Tang" (Kidney Fixedness Decoction). It is composed of: 30g of licorice (Gancao, 2 liang), 30g of atractylodes rhizome (Baizhu, 2 liang), 60g of dried ginger (Ganjiang, 4 liang), and 60g of Poria (Fuling, 4 liang). Here the liang refers to the Han-dynasty liang, each Han liang being approximately 15g today. Boil with 1 sheng of water down to 600 ml, divide into three equal portions, and take one portion three times a day.

Shenzhuo Tang treats the TCM condition of "kidney fixedness" (shenzhuo), whose symptoms are cold-damp invading downward, heaviness of the body, cold, heavy, and painful below the waist, normal appetite, no thirst, and normal urination. This formula also treats "uterine bi" (paobi), presenting with difficult urination and clear nasal discharge. It can also treat vomiting and diarrhea, lower-limb edema in pregnant women, urinary incontinence in the elderly, enuresis in both sexes, and chronic cold lumbar region with vaginal discharge in women—all cases belonging to spleen-yang deficiency with cold-damp.

In clinical practice, Shenzhuo Tang is most commonly used for lumbar muscle strain and senile arthritis (the TCM bi-pain syndrome). Most formulas in the *Golden Cabinet* are simple in composition, yet a few herbs can achieve good results. Shenzhuo Tang uses large doses of dried ginger and Poria because the main cause of this condition is cold-damp: dried ginger disperses cold, Poria drains dampness, atractylodes fortifies the spleen and percolates dampness, and licorice fortifies the spleen, boosts qi, and harmonizes the other herbs. Hence this formula is well matched for lower-limb coldness and pain caused by spleen deficiency with exuberant dampness. The patient's feeling of "body heaviness" is due to excessive dampness, which makes the limbs difficult to move.

This formula can reduce lower-limb edema. Adding 15–30g of Stephania root (Han Fangji, 1–2 liang), 15g of plantago seed (Cheqianzi, 1 liang), and 15g of Achyranthes root (Huai Niuxi, 1 liang) further enhances the edema-dispersing effect. This modified version can be used for lower-limb edema in the elderly, or edema of the lower limbs caused by ascites.

When treating lumbar pain and lower-limb arthritis, this formula may be combined with Duhuo Jisheng Pills or Ermiao Pills (or Simiao Pills); for lumbar-leg pain caused by lower-limb venous thrombosis, it may be combined with Taohong Siwu Tang (composed of peach kernel, safflower, rehmannia root, Sichuan lovage rhizome, Chinese angelica, and red peony root), and augmented with Spatholobus stem (Jixueteng), Coix seed (Yiyiren), Chaenomeles fruit (Mugua), and Eupolyphaga/ground beetle (Diebichong, Tubiechong).