Buckthorn berries are a typical anthranoid drug. Some of the substances contained are bacterially cleaved in the intestine. The cleavage products lead to decreased absorption of fluid, which means that more fluid is transported from the intestine into the blood.
At the same time, the cleavage products increase the secretion of chloride and subsequently water into the intestine. As a result, the intestinal contents are more fluid and the intestinal volume is increased, which in turn leads to an increase in intestinal motility and accelerated bowel emptying.
Buckthorn: possible side effects
When taking buckthorn berries, cramp-like discomfort of the gastrointestinal tract may occur, which must result in a dose reduction. Prolonged use may cause blood in the urine (hematuria) and electrolyte losses (especially potassium). Potassium losses may result in muscle weakness and cardiac dysfunction such as cardiac arrhythmias.
In isolated cases, harmless pigment deposits in the intestinal mucosa (pseudomelanosis coli) have been observed, but these disappear after discontinuation of the drug. Excessive use of buckthorn berries may also lead to worsening of intestinal sluggishness.
Interactions with other agents
The potassium losses already mentioned and the corresponding consequences (disturbances in heart function) of chronic use may be exacerbated if various other agents are taken at the same time. These include various diuretics (thiazide diuretics), adrenocortical steroids, agents that increase cardiac strength (cardiac glycosides), and licorice root preparations.
The effects of antiarrhythmic drugs, medications for cardiac arrhythmias, may also be affected.