Chinese Rhubarb

Chinese rhubarb contains the anthraquinone rhein, so higher doses have a stimulant laxative effect similar to that of cascara and senna. In contrast, lower doses have antidiarrheal effects because tannins (5% and 10%) in the herb have astringent effects. Laxative effects generally occur 6 to 10 hours after ingestion.

Chinese rhubarb may increase cardiac contractility, with the polysaccharides inhibiting calcium influx in the myocardium, and it may slow the progression of diabetic nephropathy and chronic renal failure. It may lower proteinuria, heal bleeding GI ulcers, and have antiviral, antibacterial, antineoplastic, and diuretic effects. The anthraquinones rhein and emodin may inhibit growth of Staphylococcus aureus. Chinese rhubarb is available as dry roots, stem parts, bark, and powder, in products such as Phytoestrol N, Abdominolon, Certobil, Cholaflux, Colax, Dragees Laxatives, Enteroton, Fam-Lax, Herbalax, Neo-Cleanse, Plantago Complex, Tisana Arnaldi, and Vegebyl.

Benefits And Uses of Chinese Rhubarb

Chinese rhubarb is used orally to treat jaundice, kidney stones, gout, headache, toothache, and skin and mucous membrane inflammation. It's also used topically to heal skin sores and scabs.

German Commission E has approved Chinese rhubarb as a treatment for constipation; lower dosages are used to treat diarrhea. In Chinese medicine, it's used to treat delirium, edema, amenorrhea, and abdominal pain.

Administration

• To treat constipation: 20 to 30 mg of rhein (1.2 g of whole roots and stem of Chinese rhubarb) as a single daily dose for a maximum of 14 days; or 1 teaspoon (5 to 6 g) of powdered root boiled in 1 cup of water for 10 minutes, taken 1 tablespoon (15 ml) at a time, up to 1 cup every day; or 1/2 to 1 teaspoon of tincture every day .
• To treat diarrhea:1/4 to 1/2 teaspoon (1 g) of powdered root boiled in 1 cup of water for 10 minutes, taken 1 tablespoon (15 ml) at a time, up to 1 cup every day; or 1/4 teaspoon of tincture once a day .
• To treat toothache: By cotton swab directly on the affected tooth.

Side Effects of Chinese Rhubarb

Adverse effects associated with Chinese rhubarb include abdominal cramping, diarrhea, nausea, vomiting, reduced gastric motility, kidney stones, hematuria, discolored urine, hypokalemia, electrolyte imbalance, weakness, dehydration, and pigmentation of the intestinal mucosa.

The oxalate in Chinese rhubarb may form an insoluble compound with calcium, which may cause kidney stones. Chinese rhubarb may increase the risk of hypokalemia when given with corticosteroids and potassium wasting diuretics.

It may increase the cardiac toxicity of digoxin or other antiarrhythmics as a result of potassium loss and effects on drug absorption. Chinese rhubarb may potentiate the effects of laxatives. It may also potentiate anticoagulant effect by reducing absorption of vitamin K.

Those with hypersensitivity to the herb or its components, pregnant patients, breast-feeding patients, and children under age 2 should avoid use. Those with intestinal obstruction or ileus, appendicitis or chronic intestinal inflammation such as gastric or duodenal ulcer, Crohn's disease, ulcerative colitis, abdominal pain of unknown origin, or a history of kidney stones should also avoid use. Limit duration of use to less than 2 weeks to avoid bowel tolerance.

Clinical considerations

• Oral ingestion of Chinese rhubarb may cause hypokalemia due to excessive diarrhea. Monitor levels of potassium and other electrolytes carefully.
• If patient has a medical condition such as small bowel disease, a stomach ulcer, or heart disease, advise him not to use Chinese rhubarb.
• If patient is taking digoxin, warfarin, a corticosteroid, or a diuretic, tell him to notify his health care provider before using Chinese rhubarb.
• If patient is also taking digoxin or another antiarrhythmic, monitor electrocardiogram results for cardiac toxicity.
• Although Chinese rhubarb has been used to treat constipation, instruct patient not to take it without medical advice and even then to use it only when needed, to help reduce likelihood of hypokalemia. Advise him to use the smallest possible dose to achieve therapeutic effect.
• If patient is also taking digoxin or another antiarrhythmic, monitor electrocardiogram results for cardiac toxicity.
• If patient is also taking an anticoagulant, watch his International Normalized Ratio closely.
• Lazy bowel syndrome may develop with prolonged use. Warn patient about laxative dependency, and instruct him not to take Chinese rhubarb for more than 2 weeks.
• Patient may experience red or bright yellow discoloration of urine.
• Use of Chinese rhubarb may interfere with diagnostic urine tests.
• Tell patient to remind prescriber and pharmacist of any herbal or dietary supplement that he's taking when obtaining a new prescnption.
• Advise patient to consult his health care provider before using an herbal preparation because a treatment with proven efficacy may be available.

Research summary

The concepts behind the use of Chinese rhubarb and the claims made regarding its effects have not yet been validated scientifically.