Dutch combining herbal products and medicines without consulting GP, warns medicines board

A staggering percentage of people in the Netherlands use herbal products in combination with other medications, without first discussing it with their healthcare professionals, the Dutch Medicines Evaluation Board (MEB) told Euractiv.

Research commissioned by the MEB revealed that almost a third of Dutch people have used herbal remedies in the past year. Of these, 81% used herbal products in combination with medications, often without fully being aware of any possible risks.

While such combinations are not necessarily a problem, the MEB launched a campaign to raise more awareness on this topic.

“Most combinations will cause no harm. However, there are exceptions,” a spokesperson for the MEB told Euractiv. In some cases, the herbs could potentially decrease the intended effect of a medicine or increase its side effects.

The MEB therefore thinks it’s wise for patients and healthcare professionals to be aware that such interactions may be possible. Research commissioned by the board revealed that 72% of users of herbal remedies do not make their GP aware of their use of alternative medicines.

“This supports the idea that users themselves should be alert to potential risks of combinations. In addition, increased awareness among healthcare professionals about high-risk combinations can be useful,” the spokesperson said.

They added that doctors and pharmacists could potentially warn patients about the use of certain herbs before they start using certain medications.

St. John’s wort’s negative impact

The Dutch National Institute for Public Health (RIVM) had previously called for caution when using supplements containing St. John’s wort, a plant native to Europe with yellow star-shaped flowers. While the RIVM said it doesn’t know how many people use herbal preparations with the plant, it said people use it to help them sleep better.

However, the institute said St. John’s wort makes some medicines less effective.

“Herbal preparations containing St. John’s wort reduce the effect of chemotherapy or agents against fungal or viral infections,” the RIVM said. On the other hand, it added that it can enhance the effects of antidepressants or tranquillisers.

While the focus of the MEB’s latest research was not on the use of herbal products instead of allopathic drugs, a previous Dutch study revealed that the Netherlands Pharmacovigilance Centre Lareb registered 1,727 adverse drug reactions (ADRs) coming from 823 herbal products between 1991 and 2021.

The authors noted that the public often perceives herbal products as less toxic than conventional drugs despite both of them containing pharmacologically active ingredients that can give rise to ADRs.

They argued that the inclusion of herbal medicinal products and herbal supplements in pharmacovigilance systems is important because a systematic approach to collecting data relevant to these substances helps doctors and regulators prevent harm.

Campaign highlighting risks

To raise awareness of the combination of herbal medicines with prescribed drugs, the MEB organised a campaign targeting healthcare professionals and users of herbal products about the potential risks of such combinations. The response has been positive, and healthcare workers noted that they found the campaign relevant as their basic knowledge on this subject was limited.

A spokesperson for Starodub, a Dutch-based company that assists pharmaceutical companies with regulatory requirements, said it was good to have such an awareness-raising campaign.

“However, such public announcements should always be done with care, as the danger exists that patients or citizens get scared of something that is still very unclear,” the Starodub spokesperson said. They added that the best approach is for similar campaigns to be based on the most recent data.

“The campaign has been an effective start in the Netherlands for increasing awareness about the topic,” the MEB’s spokesperson told Euractiv. “We think that increased attention in the future is useful to further increase awareness of the subject and notice effects in practice,” they added.

[Edited by Vasiliki Angouridi, Brian Maguire | Euractiv’s Advocacy Lab]