Laxative drugs rhubarb

L., the common garden rhubarb. Rhubarb, like Ginseng and Ephedra, is one of the oldest and most widely used Chinese drugs. Chemically it contains a most complex mixture of anthracene glycosides, the most important of which are the dimeric Sennosides. Tannins are also found which can counteract the laxative effect and at low doses (0.05-0.5 g) it is their astringent effect that predominates. Higher doses of 1-2 g have a mild laxative effect. Extracts are also used in the treatment of mouth ulcers. 

Concomitant use of Chinese rhubarb is cautioned with antiarrhythmic drugs and botanicals containing cardiac glycosides, as long-term use of Chinese rhubarb as a laxative can cause potassium loss, leading to increased toxicity of those drugs and botanicals (Drinker 2001 De Smet 1993 ESCOP 2003). 

Use of stimulant laxatives, such as Chinese rhubarb, may reduce the gastrointestinal transit time and thus reduce the absorption of orally administered drugs (Drinker 2001 De Smet 1993). 

Anthraquinone glycosides have long been used medicinally as cathartics and laxatives. Plant-derived drugs of this type include aloes Aloe species), cascara sagrada (Rhamnus purshiams), frangula (Rhamnus frangula), rhubarb (Rheum officinale), rumex or yellow dock (Rumex crispus) and senna (Cassia spp.). Many of the commercial preparations (patent medicines) based on these plants are readily available. 

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