St. Janskruid kan chemotherapie bemoeilijken.*

Apr 08 2002 - St. John's wort, the popular herbal remedy for depression, may reduce the effectiveness of chemotherapy drugs, doctors warn. St. John's wort stimulates an enzyme known as CYP3A4, which is involved in the metabolism of many drugs, including the cancer agent irinotecan, according to Dr. Ron Mathijssen of the Rotterdam Cancer Institute in the Netherlands. In doing so, the herbal supplement reduces the cancer drug's fighting power, Mathijssen reported Monday at the annual meeting of the American Association for Cancer Research in San Francisco, California. "Since about 50% of all drugs are metabolized by CYP3A4, the combination effect we found with St. John's wort and irinotecan might occur with many other anti-cancer agents," he said in a prepared statement. "So the problem is potentially more widespread than this study shows."  

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