Aim: To develop a tool to assist pharmacists and prescribers to make an initial check for potential interactions and precautions associated with the use of commonly used CAM and parenteral anticancer agents.
The use of complementary medicines (CAM) in the cancer population is higher than in the general population, with some studies estimating use as high as 70%.
Many CAM have the potential to interact with chemotherapy via a number of different mechanisms. Enquiries regarding the combined use of CAM in combination with anticancer agents are regularly received by the Medicines Information service at a tertiary cancer centre and are increasing in complexity.
Method: Commonly used CAM and intravenous anticancer agents (both chemotherapy and targeted therapies) were included. Interactions and potential precautions associated with each of the combinations were identified using a number of evidence-based complementary medicine and drug interaction resources. Additionally, general considerations not specific to an anticancer agent were identified for each CAM. The results were presented in a table to provide an easy to use tool for clinicians.
Results: Thirty four anticancer agents and 37 CAM were included. The main precaution or interaction types identified were cytochrome P450 interactions, antioxidant and antiplatelet precautions and potential immune and hormonal activity. Where potentially severe direct organ toxicity exists, this information was also included. The table is referenced and describes the nature of the evidence eg. In-vitro versus animal or human studies.
Conclusions: The CAM and anticancer agent interaction tool is a useful resource for clinicians when initially checking for interactions between CAM and cancer therapy. Further work is planned to increase the number of anticancer agents included and to consider the addition of oral anticancer agents. The table is not designed to replace the requirement for a clinician-patient discussion.