Botanical Medicine: Canadian Standards and Regulations

Heather Boon, BScPhm, PhD

Research Consultant, Michener Institute for Applied Health Sciences; Research Assistant Professor, Faculty of Pharmacy, University of Toronto, Toronto, Ontario.

Michael Smith, MRPharmS, ND

Chair, Botanical Medicine, Canadian College of Naturopathic Medicine, Toronto, Ontario.

Albert Wong, MD, FRCPC

Fellow in Psychiatry, Clarke Institute of Psychiatry, Faculty of Medicine, University of Toronto; PhD candidate, Institute of Medical Science, School of Graduate Studies, University of Toronto, Toronto, Ontario.

The use of complementary/alternative medicine (CAM) is increasing in North America. Canadian figures suggest that 42% of Canadians have used some form of CAM and that they are spending approximately $1 billion annually on CAM therapies and products that are not covered by insurance plans (1). This prevalence rate is confirmed by the most recent American survey which found that use of CAM to treat one’s “most serious health condition” had increased from 31% of the United States (US) population in 1990 to 42% in 1997 (2). Other recent developments underscore the magnitude of CAM as a health care issue in North America. The November 1998 issues of all of the American Medical Association journals (including JAMA and the Archives family of journals) were devoted to discussions of CAM, indicating an acknowledgement that physicians can no longer ignore these trends. In addition, the Office of Alternative Medicine (OAM) of the National Institutes of Health was recently upgraded to a Centre of Alternative Medicine with a subsequent increase in budget (US$50 million dollars). This paper will review the current regulatory status of botanical products in Canada.

Botanical products sold in Canada are currently regulated as either food supplements or traditional herbal medicines (THMs). Therapeutic claims cannot be made with respect to botanical products marketed as food supplements. In addition, the recommended dosage of botanical food supplements must not exceed one-quarter of therapeutic dosage levels. Products marketed as food supplements do not require cautions, contraindications, or possible adverse effect information on the label.

Botanical products marketed as THMs must be intended for self-medication only, and all active constituents must be herbal ingredients. Applications for Drug Identification Numbers (DINs) for products in the THMs category must be supported by a minimum of 2 acceptable herbal references (acceptable references are specified in the regulations) rather than based on specific levels of scientific evidence (3). It is important to note that THMs cannot receive approval for indications that are listed in Schedule A of the Canadian Food and Drugs Act, which prohibits the sale or advertisement of any food, drug, cosmetic, or device to the general public that is presented as a treatment, preventative, or cure for diseases, disorders, or abnormal physical states referred to in Schedule A including: arthritis, asthma, and depression. Currently any product that has received a DIN (including TMHs) must meet the general Good Manufacturing Practices (GMPs) established by Health Canada (4). GMPs are voluntary for manufacturers of foods (including botanical products sold as food supplements).

The use of herbs as nonmedicinal ingredients in nonprescription products is also regulated by Health Canada (5). In summary, herbs may be used as nonmedicinal ingredients provided that they do not have the same pharmacological action(s) as the medicinal ingredient(s); that the amount contained in a daily dose must not exceed 10% of the lowest therapeutic daily dose documented in traditional herbal literature; and that they are not listed in the appendix to the guideline (herbs unacceptable for use as nonmedicinal ingredients) (5).

In November 1998, the Standing Committee on Health released a report entitled “Natural Health Products: A New Vision,” which included the following recommendations:
1. that the Food and Drugs Act be amended to include a new category for natural health products (NHPs); 2. that regulation of NHPs be based primarily on safety; 3. that good manufacturing-practices guidelines specific to NHPs be established and enforced; and 4. that health claims, including structure-function claims, risk-reduction claims, and treatment claims be allowed provided there is “reasonable” evidence (that is, not limited to double-blind clinical trials) supporting the claims (6). It should be noted that these remain recommendations and that changes to the Canadian regulatory system are likely to be slow in coming.

A recent review paper by the authors identified 3 herbs that may have therapeutic effects in specific psychiatric conditions (7): St John’s wort in mild to moderate depression; Ginkgo biloba for the treatment of memory impairment associated with dementia; and black cohosh for the management of symptoms commonly associated with menopause. A number of herbs that may interact with common psychiatric medications were also identified including: chaste tree with dopaminergic drugs and Asian ginseng (Korean or Chinese ginseng) with monoamine oxidase inhibitors and stimulants. In addition, Siberian ginseng may potentiate the action of some sedatives (7). There is evidence that NHPs can cause harm (for example, death from overdoses of ephedrine-rich products made from Ma Huang) (8) and may interact with conventional therapy (for example, St John’s wort with conventional antidepressants) (7,9).

Several steps can be taken to decrease the risk of adverse effects associated with CAM. Since an increasing number of people use CAM, and approximately 20% of patients taking herbal products are also taking a least 1 conventional drug (2), physicians need to educate themselves about common therapies and products used by their patients. Patients should be asked specifically about their use of CAM; approximately two-thirds of all patients who use CAM do not disclose this use to their physicians (2,10). Finally, if patients are taking botanical herbal products, they should be encouraged to use those that comply with the regulations discussed above.

References

1. CTV/Angus Reid Group. Use of Alternative Medicines and Practices. Winnipeg: Angus Reid Group; 1997.

2. Eisenburg DM, Davis RB, Ettner SL, and others. Trends in alternative medicine use in the United States, 19901997: Results of a follow-up national survey. JAMA 1998;280:1569–75.

3. Drugs Directorate (Bureau of Nonprescription Drugs). Medicinal Herbs in Traditional Herbal Medicines. Ottawa: Drugs Directorate (Bureau of Nonprescription Drugs); 1995.

4. Drugs Directorate. Good Manufacturing Guidelines for the Manufacture of Herbal Medicinal Products. Final Version. Ottawa: Drugs Directorate; 1996.

5. Drugs Directorate (Bureau of Nonprescription Drugs). Herbs Used as Non-Medicinal Ingredients in Nonprescription Drugs for Human Use. Ottawa: Drugs Directorate (Bureau of Nonprescription Drugs); 1995.

6. Volpe JC. Natural Health Products: A New Vision. Ottawa: Report of the Standing Committee on Health; 1998.

7. Wong A, Smith M, Boon H. Herbal remedies in psychiatric practice. Arch Gen Psychiatry 1998;55:1033–44.

8. Cowley G. Herbal warning. Newsweek 1996;May 6:60.

9. Newall CA, Anderson LA, Phillipson JD. Herbal Medicines. A Guide For Health Care Professionals. London: The Pharmaceutical Press; 1996. p 296.

10. Eisenberg DM, Kessler RC, Foster C, Norlock FE, Calkins DR, Delbanco TL. Unconventional medicine in the United States: prevalence, costs and patterns of use. N Engl J Med 1993;328:246–52.

Résumé — La médecine botanique : normes et règlements canadiens