Pharmacovigilance in Herbal Medicine: A Paradigm to Drug Toxicity Monitoring in Conventional Health Care

Abstract

From prehistoric times, herbal medicine has been used by various communities and civilizations throughout the world. This trend continues to the present day. For the past several decades, herbal medicines have been increasingly consumed by people without prescription. They are traditionally considered as harmless since they belong to natural sources. Herbal formulations which have reached widespread acceptability as therapeutic agents are such as antidiabetics, anti-arthritics, aphrodisiacs, hepatoprotectives, cough remedies, memory enhancers and adoptogens. However, with a more efficient case reporting of adverse drug reactions, the hazards of herbal medicines as self prescriptions have been well recorded. In this regard the World Health Organization (WHO) has set specific guidelines for the assessment of the safety, efficacy and quality of herbal medicines. The purpose of pharmacovigilance is to detect, assess and understand, and to prevent the adverse effects or any other possible drug-related problems, which is not only confined to chemical drugs, but extended to herbal, traditional and complementary medicines, biologicals, vaccines, blood products and medical devices. Herbal pharmacovigilance should be implemented and authorities should record apart from existing information on various aspects of the single herb and/or compound herbal formulations on concomitant use with chemical drugs, adverse drug reaction, delayed or acute toxic effects, allergies etc. Most over-the-counter herbal products like ginseng have drawn great public attention but there are several case reports mentioned in the literature of adverse drug reactions of herbal drugs which are generally considered safe. In this paper, we have succinctly reviewed the various aspects associated with the pharmacovigilance of herbal medicines ranging from the pathophysiology to the various clinical elements of adverse drug reactions associated with herbal medicine.