二陈汤

o White slippery or white greasy tongue coating.

3. Tongue and pulse

• Tongue: white greasy or white slippery tongue coating.
• Pulse: slippery pulse.

4. Common modifications (this formula is the foundation for treating phlegm, and modifications are extremely numerous)

• Heat-phlegm (yellow, sticky phlegm): add Gua Lou (trichosanthes fruit), Huang Qin (scutellaria root), and Dan Nan Xing (bile arisaema) → forming Qing Qi Hua Tan Wan (Clear the Qi and Transform Phlegm Pill).
• Cold-phlegm (thin, clear phlegm): add Gan Jiang (dried ginger) and Xi Xin (asarum) to warm the Lung and transform rheum.
• Wind-phlegm (dizziness, headache): add Tian Ma (gastrodia rhizome) and Bai Zhu (white atractylodes rhizome) → forming Ban Xia Bai Zhu Tian Ma Tang (Pinellia, Atractylodes, and Gastrodia Combination).
• Food-phlegm (with food accumulation): add Lai Fu Zi (radish seed), Shan Zha (hawthorn fruit), and Shen Qu (medicated leaven).
• Qi-phlegm (plum-pit qi): add Hou Po (magnolia bark) and Zi Su Ye (perilla leaf) → forming Ban Xia Hou Po Tang (Pinellia and Magnolia Bark Combination).
• Phlegm flowing through the channels (scrofula and phlegm nodules): add Hai Zao (sargassum), Kun Bu (kelp), and Mu Li (oyster shell).

5. Cautions and clinical notes

• Contraindications:

o This formula should not be used for dry cough due to yin deficiency or for pulmonary consumption with hemoptysis, because the formula is warm and drying in nature.

o Ban Xia in this formula is toxic; although it is processed and moderated with the addition of Sheng Jiang (fresh ginger), it should still not be taken in excessive amounts or over a prolonged period.

6. Granule conversion and dose

• Calculation of total raw herb weight in the original formula:

o Ban Xia 15 g + Ju Hong 15 g + Fu Ling (poria) 9 g + Sheng Jiang 5 g + Wu Mei (mume fruit) 1 g + Zhi Gan Cao (honey-fried licorice root) 4.5 g = 49.5 g (approximately 50 g).

• Conversion to 5:1 granules:

o 50 g raw herbs ÷ 5 = 10 g granules.

• Recommended dosage:

o One dose daily, taken in two portions, morning and evening, dissolved in warm water, about 5 g per dose.

o Or as directed by a physician. Er Chen Tang is a foundational formula that is very rarely used alone in clinical practice; it is almost always modified according to the specific pattern. In such cases, the granule dosage must be recalculated based on the total raw herb weight after the physician's adjustments.