Perioperative Herbal Supplement Use in Cancer Patients: Potential Implications and Recommendations for Presurgical Screening

Nagi B. Kumar, PhD, RD, FADA; Kathy Allen, MA, RD; Heather Bell, MS, RD


Cancer Control. 2005;12(3):149-157. 

In This Article

Herbal Supplements That Cause Gastrointestinal Disturbances and Hepatotoxicity

Kava is derived from the pepper plant (Piper methysticum). Kavalactones appear to be responsible for the pharmacologic activity of kava. These include psychomotor effects, antiepileptic properties, neuroprotection, and a local anesthetic effect. In patients with Parkinson's disease, kava may interfere with the effects of levodopa and can cause a semicomatose state when given concomitantly with alprazolam.[21] This may be due to the sedative-hypnotic effect potentiated by GABA neurotransmitter inhibition. Animal studies have shown an increase in bar-biturate-induced sleep time when kava is used.[52] Peak plasma levels for kava occur 1.8 hours after an oral dose. The elimination half-life for kavalactones is 9 hours.[53] Due to the possibility that kava may potentiate the sedative effects of anesthesia, it is recommended that patients should not take kava for at least 24 hours prior to surgery.

Kava has also been reported to cause serious liver toxicity, including several deaths, which has prompted the US food and Drug Administration Center for Food Safety and Applied Nutrition to notify healthcare professionals and consumers of this potential risk in March 2002. This toxicity is particularly relevant in patients with a history of pre-existing liver disease or those receiving drugs known to have potential hepatotoxicity such as camptothecins, cyclophosphamide, EGFR-TK inhibitors, taxanes, and vinca alkaloids.[54]

Herbal supplements such as feverfew, Ginkgo biloba, echinacea, and St John's wort have been associated with oral manifestations such as aphthous ulcers, lip and tongue irritation and swelling, gingival bleeding tongue numbness, and xerostomia.[55] Essiac tea contains a combination of four herbs: burdock root (Arctium lappa), Indian rhubarb root (Rheum palmatum), sheep sorrel (Rumex acetosella), and the inner bark of slippery elm (Ulmus fulva or Ulmus rubra). Although Essiac is promoted as having other immune-enhancing and disease-fighting properties, the only documented effect is that of a laxative.[55] It has also been found to have strong emetogenic potential. The strong laxative effect and the variation in concentration of active ingredients that is dependent on preparation may lead to dehydration and electrolyte disturbances with potassium losses. Essiac should not be consumed prior to or after surgery. Belladonna herb and its preparations have been used for their antimuscarinic actions in a wide range of conditions, including the relief of gastrointestinal and urinary tract disorders associated with smooth muscle spasm, but they generally are regarded as an outmoded form of treatment. The anticholinergic effects of belladonna are xerostomia, abdominal distention, and urinary retention. This should be avoided in all patients who will undergo surgery.