Herbal drugs are a significant source of drugs used in synthetic, complementary and alternative system of medicine including Ayurveda or Traditional Indian Medicine (TIM), Siddha, Unani, Homoeopathy, Western Medical Herbalism (WMH), Traditional Chinese Medicine (TCM) and Traditional African Medicine (TAM). The World Health Organization (WHO) has identified the growing importance of Complementary and Alternative system of Medicine and issued guidelines for proper implementation of rules and regulations governing phyto or herbal drug industry in recent publication of article on heavy metal content in ayurvedic formulations in Journal of American Medical Association (JAMA).
What is phytopharmacovigilance?
Phytopharmacovigilance is an emerging issue addressing key factors related to phyto or herbal drug industry. Although pharmacovigilance best suites in the synthetic pharmaceutical drug industry, and vigilance issues related to phyto or herbal drug is part of the conventional pharmaceutical drug industry. Globalization of the Complementary and Alternative system of Medicine (CAM) and challenges like drug resistance and cost effectiveness of synthetic drugs, have forced emergence of phytopharmacovigilance.
Phytopharmacovigilance targets several key factors related to phyto or herbal drug industry. Proper identification of medicinal plants, procurement of the raw material, process of extraction, the percentage of the active ingredients and marker compounds, microbial count, heavy metal limit, finished product and trained manpower, all fall within the spectrum of phytopharmacovigilance.
Adverse drug reaction of ayurveda medicines
Although a technical term equivalent to "pharmacovigilance" does not feature in ayurvedic texts, the spirit of pharmacovigilance is vibrant throughout ayurveda's classical literature. The Brihattrayi and Laghutrayi repeatedly emphasize the major goals of pharmacovigilance, to improve patient care and safety during treatment, and thus to promote rational use of medications. These are recurrent themes of Dravyaguna, Rasa Shastra and Bhaishjya Kalpana and Chikitsa. It is probable that these basic principles of ayurveda gave rise to the common belief that ayurvedic medicines are safe.
The ayurvedic literature gives details of drug-drug and drug-diet incompatibilities based on elaborately described qualitative differences in ingredients or quantitative proportions. These factors undoubtedly prevent the onset of many otherwise unfortunate reactions. Ayurveda's Anupan therapeutic method and Shodhan pharmaceutics principles probably also contribute to the prevention of many undesired and unforeseen events. Prevention of this kind is a major goal of pharmacovigilance programmes.
According to a survey conducted by the National Center for Complementary and Alternative Medicine (NCCAM) in the USA showed that about 7,51,000 people in the United States had ever used ayurveda and 1,54,000 people had used them within the past 12 months. Broadly speaking, two categories of medicines labelled as "ayurvedic" are available in the market: firstly, classical ayurvedic formulations, which are as per described in Ayurveda Samhitas and secondly patent and proprietary formulations made of extracts of herbs.
Classical ayurveda prescribes metals and minerals as medicines given as Bhasma or in combination with plants as herbo-mineral formulations (e.g., Aarogyavardhini). Manufacturing procedures for these medicines are stringent, and adverse reactions are described when precautions are not taken while manufacturing and administering these medicines. Although these medicines are widely used in India, doubts about their long-term safety come up due to the presence of toxic metals in them and there are reports related to adverse reactions.
Nearly 21 per cent of the ayurvedic medicines tested were found to contain detectable levels of lead (most common), mercury, or arsenic. All metal-containing products exceeded one or more standards for acceptable daily metal intake. The prevalence of metal-containing products did not differ significantly by country of manufacture. Rasa Shastra products were more than twice as likely as non-Rasa Shastra products to contain metals, and several Rasa Shastra medicines manufactured in India could result in lead and/or mercury ingestion 100 to 10,000 times greater than acceptable limits.
Set up of pharmacovigilance for ASU drugs
Departments of government, hospitals, and academic institutions, involved in clinical pharmacology, clinical pharmacy, clinical toxicology, or epidemiology have been identified as the best hosts to set up and house centres. Those applying will be assessed for infrastructure and other resource requirements, since proper planning is essential to establish and run a pharmacovigilance centre successfully. Also, government support is necessary at least at the national level.
Scope of pharmacovigilance in ayurveda
The goals of ayurveda's pharmacovigilance programme are to improve:
- Patient care and safety when using ayurvedic medicines and related interventions;
- Public health and safety records of ayurvedic medicines
- Assessment of benefit, harm, effectiveness, and risk of medicines,
- Encouragement of safe, rational, and more effective (including cost effective) use, and promotion of understanding, education, and clinical training in pharmacovigilance for ayurvedic medicines and its effective communication to the public. Many cases have been reported in the recent past regarding ADRs and drug-drug interactions at various national and international forums.
CSRUISMThe WHO emphasizes that it should include traditional medicines in pharmacovigilance system and has published guidelines on safety monitoring of herbal medicines in pharmacovigilance systems in 2004. To promote the guidelines of WHO, IBN Sina Academy of Medieval Medicine & Sciences, took a novel task of improving the use of Indian originated drugs and their adverse reaction monitoring under the establishment of Center for Safety & Rational Use of Indian Systems of Medicine (CSRUISM) in 2005.
The Centre is also cooperating and assisting National Pharmacovigilance Programme for Ayurveda, Siddha and Unani (ASU) drugs, which is currently being governed under the aegis of Institute of Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurveda University, Jamnagar in collaboration with the Department of Ayush, Ministry of Health and Family Welfare, Government of India.
ConclusionA recent survey conducted by the NCCAM in the USA showed that about 7,51,000 people in the United States had ever used ayurveda and 1,54,000 people had used them within the past 12 months. Associated with this increasing use, are growing concerns about the safety of ayurvedic medicines, application of phytopharmacovigilance is must and need of the hour.
(Author is a herbal consultant)