Trust issues abound with CAM and kidney disease
Even as the medical fraternity moves towards evidence-based practices, our society continues to place their trust in complementary and alternative medicine (CAM).
CAM is a broad term which encompasses the likes of yoga, acupuncture, Ayurveda, aromatherapy, Reiki, hypnosis, homeopathy, herbal medicine, meditation, massage therapy and chromotherapy. Evidently, those involving external manipulations rarely cause kidney complications. It is usually the ingested herbal remedies or supplements which cause kidney damage.
Speaking at the recent 15th Annual Dialysis Meeting 2018, Dr Suryati Yakob, specialist in internal medicine and nephrology, Hospital Selayang, said herbal remedies and supplements may cause acute kidney injury, nephrolithiasis, rhabdomyolysis, Fanconi syndrome, urothelial carcinoma and chronic kidney disease. These conditions arise as a result of factors related to the herbal ingredients themselves either the intrinsic toxicity of the herbs, incorrect identification, adulteration or contamination by heavy metals. Sometimes, complications arise as a result of overdosage or drug-herb interaction. Finally, patient factors such as their existing clinical condition, gender and age also contribute to their risk of kidney injury from herbal ingestion.
Perhaps the most infamous herbal ingredient is aristolochic acid (commonly found in the flowering plant family of Aristolochiaceae/birthworts), which causes nephropathy and is positively linked to urothelial malignancies, liver and other cancers. [Kidney Int 2008;74(2):158–169, Sci Transl Med 2017;9(412)]
A case of mistaken identity
One of the problems involved in herbal remedies is in the acquisition and composition of its ingredients. While pharmaceuticals are heavily regulated, and the entire processing chain is documented and mostly automated, the same may not be true for herbal remedies and supplements.Herbal remedies are commonly traded by their generic names and not scientific names. This opens up the possibility of accidental substitution, especially when raw ingredients are hard to come by or are expensive. One such instance is the use of Aristolochia fangchi (guang fang ji) in place of Stephania tetrandra (fen fang ji or han fang ji). Aristolochia fangchi (in fact, all members of the Aristolochia genus) contain aristolochic acid, which is a potent mutagen and nephrotoxic phytochemical. [Mutagenesis 2002;17(4):265–277]
In a famous case in the 1990s, Belgians taking a herbal preparation for weight loss began showing symptoms of kidney failure. Instead of containing the plant Stephania tetrandra, the herbal pills contained derivatives of Aristolochia fangchi. [N Engl J Med 2000;342:1686–1692]
Another example similar in nature is the case of Caulis aristolochiae manshuriensis (guan mu tong) which was inadvertently used in place of Lardizabalaceae (mu tong) in a traditional Chinese medicine formula, again leading to nephrotoxicity in patients. [Clin J Am Soc Nephrol 2018;13(10):1605–1611]
Suryati acknowledged that CAM is used widely all over the world and by all walks of life. While local data is missing, the US Centers for Disease Control and Prevention (CDC) notes that the bulk of people consuming CAM fall within the 40- to 69-year age group. [Natl Health Stat Report 2008;12:1–23] However, she noted that many of the ingredients used in CAM do not have an established safety profile. She called for stricter laws in monitoring the production and use of herbal medication and supplements. With the lack of oversight on these products, it may be best to avoid them.