St. John’s Wort has been used for centuries to treat depression. Its active ingredients, hypericin and pseudohypericin, are isolated from Hypericum perforatum. It is known to have medicinal properties, including antidepressant, antimicrobial, and antiviral effects.¹ The most alarming fact about St. John’s Wort is that regardless of its status as an herbal dietary supplement, it is a drug.
Nearly 100 prescription drugs are known to interact with St. John’s Wort significantly.2 Because this drug is sold over the counter, pharmacists often have no control over who purchases this product and little opportunity to intervene if there is potential for a problem to occur.
As with many other drugs, St. John’s Wort has been shown to cause serious interactions with such prescription medications as antidepressants, immunosuppressants, antimicrobials, and anticoagulants, as well as antiepileptic, anticancer, and antiretroviral drugs.
Through its activity on the cytochrome P450 metabolism system it can also severely decrease the effectiveness of many medications, including immunosuppressants and drugs used to treat high blood pressure and high cholesterol.3 In some cases, when St. John’s Wort was given with antidepressants, severe symptoms of serotonin syndrome were reported.4 These kinds of interactions can lead to unwanted and even fatal clinical consequences.
Lack of regulation
Classified as an OTC herbal supplement, St. John’s Wort is not under FDA regulation. The concentration and purity of the product’s content can vary from brand to brand, and therefore its effectiveness is not guaranteed.
Furthermore, the packaging of St. John’s Wort often includes misleading labels.5 Studies have revealed a discrepancy between the product’s actual contents and the label on the bottle. It turned out that the amount of the active ingredient hypericin varied greatly from product to product, ranging from 56% to as high as 130% of the stated amount.6
Randomized control trials examining the efficacy of St. John’s Wort have produced inconsistent results. Some placebo-controlled trials have shown only marginal benefit, while others found beneficial effects similar to those of prescription antidepressants.7
There is a lack of evidence about its effectiveness as a depression treatment. It could worsen a patient’s existing condition, and in severe cases, may result in suicide. Equally disturbing, if patients with no diagnosis of depression are taking high doses of St. John’s Wort unknowingly, overdose can result.
A petition to change status
Healthcare professionals who know the issues surrounding the use of this product cannot ignore the problem. St. John’s Wort can be a dangerous drug, and it needs to be treated as one. In Germany and Ireland, it has already been made a prescription-only drug.
FDA has received a citizen petition to change the status of St. John’s Wort from “herbal dietary supplement” to “behind pharmacy counter” (docket number FDA-2013-P-0066/CPI). Such a change, once effected, will give pharmacists control over patient purchases of the drug, allow them opportunity to identify potential problems, and enable them to provide counseling.
Serious consequences to patients can be avoided when pharmacists take on this responsibility. Concerned pharmacists should write to FDA to support this petition for change in the law.
Acknowledgements: Aglaia Panos PharmD; Judea Mintalar, PharmD Candidate 2013, Touro-CA.
2. Tsai HH, Lin HW, Simon Pickard A, et al. Evaluation of documented drug interactions and contraindications associated with herbs and dietary supplements: A systematic literature review. Int J Clin Pract. 2012 Nov;66(11):1056-1078. doi: 10.1111/j.1742–1241.2012.03008.x.
3. Borrelli F, Izzo AA. Herb-drug interactions with St John's wort (Hypericum perforatum): An update on clinical observations. AAPS J. 2009 Dec;11(4):710–727. doi: 10.1208/s12248-009-9146-8. Epub 2009.
5. Ganzera M, Zhao J, Khan IA. Hypericum perforatum — chemical profiling and quantitative results of St. John's Wort products by an improved high-performance liquid chromatography method. J Pharm Sci. 2002;91:623–630.
Yanhui Zeng is a 2013 PharmD candidate at Touro University-CA. Contact her at [email protected].