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.