The prevalent misconception that natural medicines are harmless must be refuted, and emerging evidence of adverse reactions to St John's Wort herbal products are potentially serious, an expert in complementary medicine has warned.
St John's Wort (Hypericum perforatum) is used as an alternative treatment for depression. But, on the recommendation of the Irish Medicines Board, the over-the-counter sale of the herbal extract will be banned and it will become a prescription-only product.
Writing in the current edition of the Lancet, Dr E. Ernest of the Department of Complementary Medicine at the University of Exeter, reviewed case reports of negative reactions to St John's Wort, which included bleeding and interference with levels of prescription drugs in the blood.
Dr Ernest warned that doctors must be aware that the administration or discontinuation of hypericum extracts could significantly affect blood concentrations of many prescribed medicines.
"Patients must be encouraged to discuss their use of herbal remedies with their physician, and the prevalent misconception that natural always equates with harmless must be effectively refuted," he said.
"Regulatory bodies should perhaps take a fresh look at whether herbal medicines need regulation, since the perception of `risk-free' may reflect incomplete understanding."
A spokesman for the Irish Medicines Board welcomed the report, which he said concurred with the board's view.
The Green Party TD, Mr Trevor Sargent, who is campaigning against the decision to make St John's Wort prescription-only, said there was no doubt that the herbal extract needed to be regulated, but it could not be using the regulations currently applied to pharmaceutical products.