Published May 15, 1985; Revised March 13, 1990; April 19, 1991, and September 21, 1991.
List of German Commission E Monographs (Phytotherapy)
Liquiritiae radix, licorice root.
Licorice root consists of unpeeled, dried roots and stolons of Glycyrrhiza glabra L. [Fam. Fabaceae], as well as their preparations in effective dosage. The unpeeled roots contain at least 4 percent glycyrrhizic acid and 25 percent water-soluble matter. Licorice root also consists of peeled, dried roots and stolons of G. glabra L. [Fam. Fabaceae], as well as their preparations in effective dosage. The peeled roots contain at least 20 percent water-soluble matter.
The root contains several flavonoids of flavanone and isoflavanone derivatives in addition to the potassium and calcium salts of the glycyrrhizic acid. It also contains phytosterols and coumarins.
For catarrhs of the upper respiratory tract and gastric/duodenal ulcers.
Cholestatic liver disorders, liver cirrhosis, hypertonia, hypokalemia, severe kidney insufficiency, pregnancy.
On prolonged use and with higher doses, mineralocorticoid effects may occur in the form of sodium and water retention and potassium loss, accompanied by hypertension, edema, and hypokalemia, and, in rare cases, myoglobinuria.
Potassium loss due to other drugs, e.g., thiazide diuretics, can be increased. With potassium loss, sensitivity to digitalis glycosides increases.
Unless otherwise prescribed:
Average daily dosage:
About 5 - 15 g of root, equivalent to 200 - 600 mg of glycyrrhizin; As Succus liquiritiae:
0.5 - 1 g for catarrhs of the upper respiratory tract, 1.5 - 3 g for gastric/duodenal ulcers; equivalent preparations. Mode of Administration Powdered root, finely cut root or dry extracts for infusions, decoctions, liquid or solid dosage forms for internal use (Succus liquiritiae).
Not longer than 4 - 6 weeks without medical advice. There is no objection to using licorice root as a flavoring agent up to a maximum daily dosage equivalent to 100 mg glycyrrhizin.
According to controlled clinical studies, glycyrrhizic acid and the aglycone of glycyrrhizic acid accelerate the healing of gastric ulcers. Secretolytic and expectorant effects have been confirmed in tests on rabbits. In the isolated rabbit ileum, an antispasmodic action has been observed at concentrations of 1:2500 - 1:5000.