当归四逆汤

3. Tongue and pulse

• Tongue: Pale tongue with white coating.
• Pulse: Deep and fine, or faint and verging on expiration.

4. Common modifications

• For prolonged internal cold, or cold-type hernial abdominal pain: add Wu Zhu Yu (evodia fruit) and Sheng Jiang (fresh ginger), forming Dang Gui Si Ni Jia Wu Zhu Yu Sheng Jiang Tang (Dong Quai Four Rebellious Powder Plus Evodia and Fresh Ginger Decoction), to strengthen the effect of warming the middle, dispersing cold, downbearing counterflow, and stopping vomiting.
• For severe pain from blood stasis: add Chuan Xiong (chuanxiong rhizome), Tao Ren (peach kernel), and Hong Hua (safflower) to invigorate blood and transform stasis.
• For dysmenorrhea in women: add Ai Ye (mugwort leaf) and Xiang Fu (cyperus rhizome) to warm the uterus and regulate menstruation.
• For Raynaud's disease or chilblains: add Huang Qi (astragalus root), Hong Hua (safflower), and Ji Xue Teng (spatholobus stem) to boost qi, invigorate blood, and unblock the collaterals.

5. Cautions and clinical notes

• Contraindications:
  • Absolutely contraindicated in yang-depression reversal-heat patterns (cold limbs together with burning heat in the chest and abdomen, vexing thirst, and a red tongue).
  • This formula is used for blood deficiency with cold congealing; it is not suitable for repletion heat patterns or for yin deficiency with internal heat.

6. Granule conversion and dose

• Calculation of the total raw herb weight of the original formula:
  • Dang Gui 12 g + Gui Zhi (cinnamon twig) 9 g + Bai Shao (white peony root) 9 g + Xi Xin 3 g + Tong Cao 6 g + Da Zao (jujube) 8 g + Zhi Gan Cao (honey-fried licorice root) 6 g = 53 g.
• Converted to 5:1 granules:
  • 53 g raw herbs ÷ 5 = 10.6 g granules.
• Recommended dose:
  • One dose daily, taken in 3 portions dissolved in warm water, about 3.5 g per portion.
  • Or as directed by a practitioner, who will modify the formula according to the severity of the patient's blood deficiency and cold congealing; in that case the total raw herb weight must be recalculated accordingly.