Potential of chemotherapy-herb interactions in adult cancer patients

Goals of work: The purpose of this study was to examine the specific herbs or vitamins (HV) used by patients receiving chemotherapy. Specifically, the following aspects were investigated: (1) HV use among adult cancer patients receiving chemotherapy, (2) the frequency of potential chemotherapy-HV interactions, (3) communication patterns between oncologists and their cancer patients taking HV, and (4) patients' reactions to two hypothetical scenarios of chemotherapy-HV interactions. Patients and methods: Adult cancer patients receiving chemotherapy at a university-based outpatient clinic over a 1-month period were sent a validated eight-page questionnaire regarding the use of complementary/alternative medicine, focusing on HV use. A total of 76 patients participated; relevant medical information was obtained from study participants' charts. The chemotherapy received was compared with HV use to assess for potentially detrimental chemotherapy-HV interactions. Results: HV use in patients receiving chemotherapy was common (78%), with 27% of the study participants being at risk of a detrimental chemotherapy-HV interaction. Most patients (>85%) would discontinue their HV or ask their medical oncologist for advice if a detrimental chemotherapy-HV interaction was suspected. Although most patients discussed HV use with their oncologist, the majority also relied on their friends and naturopathic physician for information regarding HV. Conclusions: Considerable potential exists for detrimental chemotherapy-HV interactions. Methods to improve communication of HV use between cancer patients receiving chemotherapy and health-care practitioners are necessary to identify and minimize the risk of these interactions.