Drug interactions with Natural Health Products: A Discussion Paper (November 2001)

1.0 Executive Summary

Almost half of all Canadians use complementary/alternative medicine (CAM), including natural health products (NHPs), in the management of their health. This widespread use means that many Canadians are using NHPs in conjunction with conventional medications, which raises concerns about potential NHP/drug interactions. The purpose of this report is to provide a broad overview of NHP/drug interactions from a Canadian perspective to facilitate discussion and identification of priority needs in this area. The report is structured around four main theme areas:

1. NHP/drug interactions from a biomedical perspective

2. clinical issues associated with identifying NHP/drug interactions and counseling patients about them

3. current health care system and policy issues, including a comparison of systems for reporting NHP/drug interactions in Canada, the United Kingdom and Australia

4. issues associated with transferring knowledge about NHP/drug interactions (from patients to practitioners to national reporting centres and back again)

At the end of the discussion, the authors identify the following priority needs:

• support for basic, clinical and epidemiological research about NHP/drug interactions

• communication with and education for health care practitioners (conventional and CAM), as well as Canadian consumers about NHP/drug interactions

• the development of a Canadian NHP/drug interaction reporting system that meets the needs of health care practitioners, researchers, patients, policy makers, the NHP industry and the pharmaceutical industry (This may involve changes to the current ADR reporting system or the design of a new, separate system for reporting suspected NHP/drug interactions. In addition, discussion about who will be eligible to report suspected NHP/drug interactions - as well as what information will be required as part of each report - is necessary.)

• the development of an effective knowledge transfer system to facilitate the reporting of NHP/drug interactions and the ability of health care practitioners and patients to access information that has been reported in a reliable and timely manner