Complementary medicine use during cancer treatment and potential herb-drug interactions from a cross-sectional study in an academic centre

Abstract

Complementary medicine (CM) is used by one third to one half of cancer patients throughout the world. The objective of this study was to describe the prevalence of CM use and the potential for interactions with cancer treatments in an academic oncology centre. A cross-sectional study was conducted among patients undergoing current cancer treatment. Among 132 included patients, 56% had used CM since their cancer diagnosis and 45% were using CM during cancer treatment at the time of the survey. The main CM used were green tea (35%), herbal tea (35%), homeopathy (27%), dietary supplements (27%), and herbal medicines (27%). A small majority of patients (58%) spontaneously mentioned the use of CM to their oncologist. Of 42 identified combinations of concomitant use of biologically based CM and anticancer agents among the study patients, the potential for pharmacokinetic interactions of clinical relevance was not expected in 17 combinations (40%), hypothetical and deemed unlikely in 23 (55%), and of probable low clinical relevance in 2 (5%). Considering the high prevalence of CM use, active enquiries should be made by healthcare professionals to detect symptoms that may relate to CM tolerance and effects or that suggest interactions between CM and cancer treatments.

Biologically-Based Complementary and Alternative Medicine (CAM) Use in Cancer Patients: The Good, the Bad, the Misunderstood

“…Other studies emphasize the danger of mixing CAM with prescribed medicines. Although the potential for adverse reactions most definitely exist, it is difficult to estimate the true risk given limited reporting and essentially non-existent quality control over the CAM utilized, as well as the inherent difficulty in distinguishing disease symptoms, CAM effects, and effects of cancer treatment (7).…”

“…Biologically-based CAM (BB-CAM) approaches are used by cancer patients for a number of reasons, including cancer prevention; cancer treatment; strengthening of the immune system; improving well-being; and alleviating symptoms of either the disease or disease treatment, such as nausea, insomnia, and pain (7,11). While numerous studies exist looking at the effects of supplements and herbals currently used as CAM on cell culture and or animal models, much less literature is available showing the long terms effects on patients using these much less on patients using them in combination with other therapies.…”

“…Supplements, such as milk thistle (silybin), licorice, soy, black cohosh, and curcumin could have estrogenic effects and therefore are a concern in hormone-sensitive cancers (7,72,74). However, evidence of adverse effects in patients has not been established.…”

“…In a cohort of 153 patients using both dietary supplements and chemotherapy, suspected drug interactions were found in 82 (54%) of patients but only one interaction was potentially clinical significant and no patient demonstrated adverse effects (22). Similarly, an analyses of 42 and 84 patients and found multiple theoretical interactions but no evidence of clinical consequences (7,75). Nonetheless, the existence of potential interactions emphasizes the importance of good communication between patient and provider and the need for careful attention to dosing.…”

Clinical Pharmacists in Chronic Care

“…Cancer cachexia (anorexia, weight loss, loss of adipose tissue and skeletal muscle) is reported in 30%-80% cancer patients and causes 20% of all cancer deaths [379]. Worldwide, some 60%-80% people depend on alternative medicines [380][381][382], which is also true for nearly 40% to 70% European [383,384], 50% Italian, 40% Korean, 30% British [385] and up to 87% of Australian cancer patients [386]. Use of unapproved/ unlabeled/wrong herbal treatment is not uncommon [387,388] and also drug interactions reported phytotherapeutics in oncology [389].…”