Findings of a recent large population survey suggest that 1 in 3 adults in this country (approximately 72 million people) uses 1 or more complementary and alternative medicine (CAM) modalities during any given year.1 Many CAMs are widely regarded as safe on the basis of their established uses in traditional systems of medicine over centuries or longer and their current widespread use in the United States and other Western countries. Unfortunately, there is limited reliable information on potential risks associated with the majority of these approaches.2,3
All herbal medicines and other natural products contain biologically active constituents that can potentially cause adverse effects or interact with medications, other natural products, or foods. The inappropriate or unskillful use of somatic and mind-body therapies can also harm patients.
Here I summarize information on tolerability, contraindications, adverse effects, and frequently encountered interactions associated with herbals and other natural products. I also briefly review safety issues encountered when somatic and mind-body therapies are used to treat or self-treat psychiatric disorders.
A significant percentage of those who receive treatment from a CAM therapist or who self-treat with herbals or other CAM modalities do so for a specific mental health problem.4 As many as 60% of persons in whom a severe mood or anxiety disorder has been diagnosed use herbals or other CAM modalities concurrently with prescription medications. Few patients, however, disclose CAM use to their physician.5-7 This results in potentially serious safety problems when adverse effects or interactions interfere with response to pharmacological treatment or exacerbate a preexisting medical or psychiatric disorder.
Emerging safety standards
Until recently, the absence of rigorous federal quality and safety standards for natural products has resulted in inconsistent importing and manufacturing practices. There have been complex safety issues, including adulteration with synthetic drugs, pesticides, heavy metals, or other potentially toxic substances, and failure to meet stated contents of bioactive constituents.8,9 Imported Chinese herbal medicines, for example, are commonly adulterated with steroids, phenobarbital, acetaminophen, and other drugs.10
The FDA is working on initiatives intended to improve standards of quality, safety, and evidence for natural products. The goal is to develop and implement stringent standards of quality, efficacy, and safety of biologically active natural products that are used medicinally. Updated announcements of FDA safety warnings on herbals and other natural products can be found at www.cfsan.fda.gov/~dms/ds-warn.html.
Most herbal supplements are generally well tolerated and have a relatively low incidence of adverse effects, especially when compared with prescription medications. However, the literature is incomplete, especially with regard to use in young children, pregnant women, women who are breastfeeding, and patients with significant liver or kidney disease, where maximum safe doses have not been clearly defined. In addition to general adverse effects, certain herbals used to treat mental health problems can potentially cause or exacerbate psychiatric symptoms.