Herbal Drug Interactions

Use of complementary and alternative medicines (CAM) for preventive and therapeutic purposes has increased tremendously in the last two decades internationally. The manufacturers of these products are not required to submit proof of safety or efficacy to the Food and Drug Administration. As a result, the adverse effects and drug interactions associated with them are largely unknown. In this chapter, the author presents interactions of herbal medicines with other medicines (herbal or non-herbal). A large number of herbal drugs, including from single drug to a variety of mixtures have been used to treat kidney disorders. Herb-herb or herb drug interaction has been reported intensively during last decade, therefore it becomes important to keep an eye on the use of combination herbal therapy in order to avoid serious results because of interactions with each other. Due to the growing awareness about the interactions and side effects of herbal drugs/supplements over the past few years, regulatory bodies are working on these issues and pharmacopoeias are being developed for reference.

How to Search and Critique Scientific Evidence for Decision-Making

A clinical decision on the use of complementary and alternative medicine (CAM) should be made based on evidence-based medicine (EBM) together with practitioner's knowledge and experiences. This chapter describes the process of EBM, including how to address a clinical question, do a systematic search for appropriate evidence with key search terms, appraise the evidence and make a clinical decision on CAM applications. An effective literature search should be performed by using a structured search strategy in searching biomedical and CAM databases, such as the National Center for Complementary and Alternative Medicine (CAM Citation Index). Few standard tools are recommended to evaluate the quality of CAM studies, i.e. the CONSORT extension for herbal interventions and STRICTA for RCTs of acupuncture. Additionally, some guidelines for designing RCTs in Chinese herbal medicine (CHM) can also be adopted to critique CAM literature. A clinical decision on choosing optimal CAM for patient care should be based on the current best evidence emerged from the EBM process.

Integrative Medicine and Prospective Research on CAM

There is a link between integrative medicine (IM) and prospective research on complementary and alternative medicine (CAM). IM is the future direction of CAM and research is needed to support clinical practice. Meaning of IM, proposed models of IM, and existing research on IM will be presented. Prospective research on CAM will cover methodologies presenting randomised controlled trials, harms studies of CAM in kidney disease, and a gap of CAM research. Study design and outcome measures are current challenges in CAM/IM research. Several networks of CAM research worldwide are still working on them and have proposed possible alternative approaches, such as pragmatic clinical trials and cohort multiple randomised controlled trials. These approaches would solve some limitations of randomised controlled trials in CAM research.

Economic Evaluation of CAM Use

Economic evaluation (EE) of health care interventions has been used to inform and affect policy decision-making by considering both costs and outcomes of the interventions. National guidelines in many countries consider cost-effectiveness evidence for making recommendations of healthcare interventions. In such case, EE of complementary and alternative medicine (CAM) is crucial to guide reimbursement decision-making. However, there is currently a lack of cost-effectiveness evidence of using CAM for kidney diseases. There are three types of full EEs, including a cost-benefit, cost-effectiveness, and cost-utility analysis, of which, results of cost-utility analysis is preferred and widely used by healthcare authorities in several developed countries. General approaches for EE of conventional medicine are likely to be applied to assess economic outcomes of CAM for kidney diseases. This chapter depicts the overall principles of EEs, interpretations of economic results and summaries the currently available EE for CAM.

Efficacy and Safety of CAM in Kidney Diseases

The evidence of benefits and safety of complementary and alternative medicine for kidney diseases are still dubious to both practitioners and general public. Chinese herbal medicines are the main CAM in treating chronic kidney disease as an adjunctive therapy to conventional medicine. Several meta-analyses of randomised controlled trials assessing the efficacy of CHM reported that Astragalus and Cordyceps seem to have a beneficial effect on the kidneys. Acupuncture, yoga and aromatherapy may alleviate symptoms in patients with ESRD, such as pain, anxiety and pruritus. This evidence should be interpreted with caution due to several limitations of the RCTs of CAM, i.e., small sample sizes, unclear randomisation and blinding. Acute kidney injury is the common nephropathy caused by herbal and dietary supplements, e.g. aristolochic acid. Dietary supplements may induce uncontrolled hyperkalemia and hyperphosphatemia in patients with advanced CKD. Unregistered herbal products from India and China may be adulterated by conventional medicines and heavy metals, which could cause AKI.

General Approach to Evaluating Beneficial and Adverse Effects of CAM Use in Kidney Diseases

This chapter will address the issue of how to evaluate benefits and nephrotoxicity of complementary and alternative medicine (CAM) in chronic kidney disease, dialysis therapy, kidney transplantation, and urolithiasis. Serum creatinine, proteinuria and estimated glomerular filtration rate are standard parameters to assess kidney function. Serum creatinine is used in evaluating acute kidney injury, which is the most common nephropathy from using herbal medicine. Assessment of electrolyte imbalance and urolithiasis is included in this chapter. The modified Naranjo algorithm has been proposed as a way to evaluate renal adverse effects of herbal medicine due to a lack of disease-specific causality assessments in herbal use. Measurement of humanistic outcomes is mentioned in this chapter. The SF-36 is commonly used in evaluating quality of life in CAM users and patients with kidney diseases. The MYMOP2 is to assess individual's symptoms in CAM use and might be used in this population.

CAM Use From Western and Asian Perspectives

This chapter will discuss the impact on the provision and integration of complementary and alternative medicine (CAM) into the patient's medical pathway and in turn, the prevalence of usage, not only for treatment but also prevention. Similarities and differences of these issues between Western and Asian perspectives will be presented. The authors will provide an overview of regulatory organisations which influence this provision, as well as advertising within the cultures which will have impact on belief of efficacy, which in turn will increase the placebo effect (thereby increasing efficacy). Due to a lack of evidence for CAM advertising in Asian cultures, further research is needed.

An Overview of Complementary and Alternative Medicine

A treatment that is not recognised as conventional medicine is frequently referred to as part of complementary and alternative medicine (CAM) methods. This Chapter will provide an overview of the several CAM definitions currently proposed and the types of CAM methods. The prevalence of CAM use and the characteristics and attitudes of CAM users will be also explored with a focus on patients with kidney diseases. The reasons for CAM use and the literature on the placebo effects as a debated hypothesis of CAM mechanism of action is presented.

CAM Recommended by Standard Guidelines for Chronic Illnesses

This chapter will focus on guidelines for clinical practice that mention a range of Complementary and Alternative Medicine (CAM) techniques. After exploring the definition and grading of clinical practice guidelines as a decision-making tool, the CAM methods included in the review will be described. A definition of chronic diseases will be provided and an overview of the current clinical practice guidelines on a number of prevalent conditions will be presented. Guidelines released by several international regulatory organisations will be compared in order to detect which CAM techniques have been or not been recommended for chronic illnesses in different countries. The challenges in implementing and appraising guidelines will be finally discussed.

An Overview of Publications of Complementary and Alternative Medicine Research

This chapter presents an overview of the quantity and quality of clinical research in CAM and publication bias. Descriptive studies and their systematic reviews on CAM, e.g., prevalence and reasons for CAM use, have been widely conducted worldwide. The findings of the efficacy of herbal medicine, traditional Chinese medicine and acupuncture for treating various illnesses, have been highly published. Publications of CAM safety are limited. A number of clinical studies of CAM in treating kidney diseases were lower than other illnesses. Studies of Ayurveda and other CAMs are still lacking. The quality of CAM publications is described based on systematic reviews of assessing CAM publications. Publication bias is explained in terms of selective publications and location bias, language bias and conflict of interest. The mainstream journals are more likely to publish positive findings. Predatory open access and recommendations for assessing predatory journals are addressed in this chapter.