The New York Times
February 10, 2000
Popular Herb Becomes Target Of a Warning
WASHINGTON, Feb. 10 (Reuters) -- St. John's wort, an herb commonly used by people to treat themselves for depression and anxiety, can interfere with a crucial drug used in AIDS cocktails as well as a drug used for transplant patients, researchers engaged in a pair of studies said today.
Patients taking the AIDS drug, indinavir, sold by Merck & Company under the name Crixivan, were warned to be particularly careful about taking St. John's wort.
Dr. Stephen Piscitelli of the National Institutes of Health, who led one of the studies, said, "When St. John's wort and the protease inhibitor indinavir are taken together, the levels of indinavir in the blood drop dramatically."
That could allow the AIDS virus to strengthen or, worse, start developing resistance.
"Patients and health care professionals need to be aware of this interaction," said Dr. Judith Falloon of the National Institute of Allergy and Infectious Diseases. "Most people taking medications to treat H.I.V. infection should avoid' using St. John's wort."
It is well known that what patients eat and drink can affect the way drugs are absorbed and used by the body. For example, grapefruit juice is known to increase the effectiveness of some H.I.V. drugs. Further, some of those drugs must be taken with food, while others must be taken on an empty stomach.
Other research has shown that patients who take herbal or other alternative treatment often do not tell their doctors about it, in part for fear they will disapprove.
Dr. Piscitelli's study is being published in the medical journal Lancet which quoted him as saying: "There is a misconception that herbal products like St. John's wort are safe, but this study demonstrates that they can be dangerous interactions when taken with other drugs prescribed to treat medical conditions. It is important for patients to tell their health care providers about their use of herbal products and complementary medicines."
Dr. Piscitelli has seen reports on how St. John's wort affects the body, and feared that it might affect the protease inhibitor class of drugs used in treating H.I.V. infection.
His team tested eight healthy volunteers, first giving them three daily doses of Crixivan alone on an empty stomach, testing levels of the drug in their blood and then adding capsules of St. John's wort.
"The results were dramatically conclusive," Dr. Piscitelli said. "All the participants showed a marked drop in blood levels of indinavir after taking St. John's wort. The drop ranged from 49 percent to 99 percent."
Protease inhibitors are often crucial to making H.I.V. drug cocktails work. They can keep the virus suppressed and keep patients healthy, but only if all the drugs are taken correctly. If drug levels fall, for instance, if something like St. John's wort interferes or if the patient misses a few doses, the virus not only resurfaces with a vengeance but can mutate into forms that resist the drugs.
In the second report involving St. John's wort, Frank Ruschitzka and colleagues at University Hospital in Zurich said it could also interfere with cyclosporine, a drug used to keep transplant patients from rejecting their new organs.
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