August 9, 2000
St. John's wort, the popular herbal supplement used to treat mild to
moderate depression, may interfere with some prescription drugs. The Food
and Drug Administration (FDA) issued a public health advisory on St. John's
earlier this year in response to a study conducted by the National Institutes of Health (NIH).
St. John's wort was found to interfere with indinavir, a drug used to treat HIV, and cyclosporine, which is used to reduce the risk of organ transplant rejection. The herbal supplement also may interfere with birth control pills and other prescription drugs used to treat conditions such as heart disease, depression, seizures and certain cancers.
The use of St. John's wort has increased tremendously in recent years. Sales in the United States surged by almost 4,000 percent from $10 million in 1995 to $400 million in 1998. Although widely distributed in pill form, it is now available in teas, juices and snack foods. In Germany, doctors prescribe St. John's wort more often than the antidepressant Prozac.
Does it work?
St. John's wort has been shown to be effective in treating mild to moderate depression with fewer side effects than standard antidepressants. There is no data about its effectiveness in treating severe depression or how well it compares with newer antidepressants. More research is needed to compare extracts and different extract formulas with standard antidepressants.
The NIH - in cooperation with the Center for Complementary and Alternative Medicine, the National Institute of Mental Health and the Office of Dietary Supplements - is currently conducting a clinical trial on the effectiveness and safety of St. John's wort. The agencies are studying the use of hypericin (an active ingredient in St. John's wort) in the treatment of patients with major depression. A total of 336 patients will be followed over a period of two to six months at two sites in the United States. The study will compare the effects of hypericin, a placebo and a newer antidepressant.
There is a wide range of potency and purity in the different extracts of St.John's wort that are available. Researchers have found that most brands contain lower potency than is listed on the label. In some cases, the potency is less than half the promised amount -- even as low as 20 percent. Standardized products contain .3 percent hypericin.
Origins of the herb
Use of St. John's wort dates back many centuries and is surrounded by
much folklore. Greeks used it to fight fevers and evil spirits. The scientific
name comes from the Greek words hyper, which means "over," and eikon, meaning
"ghost." In pre-Christian rituals in England, the plant was used to protect
a house from evil spirits and to banish witches. It was thought that a
person would be protected from death during the following year by putting
a piece of the plant under a pillow on St. John's Eve, then the Saint would
appear in a dream and give his blessing. The plant's common name reflects
the fact that
its flowers typically bloom around the birthday of St. John the Baptist on June 24.
St. John's wort also has been used as a folk remedy for centuries to treat everything from wounds, headaches, gout and kidney problems, to nervous disorders. Native Americans used several species of St. John's wort to treat diarrhea, wounds and snakebites. In more recent times in the United States, the plant was not well known until after the 1900s. In 1959, it was first studied for its ability to fight bacteria.
Other possible problems and complications
The long-term effects of using St. John's wort are not known. Although side effects are not common, they can include gastrointestinal discomfort, fatigue, dry mouth, dizziness, skin rash and hypersensitivity to sunlight. St. John's wort should not be used with alcohol, narcotics, amphetamines, anticoagulants, antibiotics or cold and flu medicines such as pseudoephedrine. It should not be used with other antidepressants because it could cause serotonin syndrome -- a potentially fatal complication involving changes in thoughts, behavior, autonomic and central nervous system functioning caused by an increase in serotonin activity. People with severe depression or manic depression and women who are pregnant or breast-feeding should not use St. John's wort.
As part of its overall mission, the American Cancer Society recognizes the growing public interest in the area of complementary and alternative methods and is committed to providing the public with a reliable guide to selecting and using these treatment methods wisely. The Society has published a new book, The American Cancer Society's Guide to Complementary and Alternative Cancer Methods, available in bookstores nationwide. The book is designed to help people make educated decisions about the use of complementary and alternative treatments, including herbs vitamins and minerals.
This comprehensive, encyclopedic-type guide includes more than 200 entries
that provide critical information about claims, what they involve, historical
background, recent research findings, side effects, drug interactions and