Health danger of herbal pills that interfere with medicine
MILLIONS of people could be risking their health by taking herbal remedies and prescription drugs at the same time, scientists warn.
Statins, warfarin and other common drugs can interact with health supplements, producing dangerous side effects or reducing the drugs’ powers, they said last night.
Herbal treatments such as St John’s wort, ginseng and chamomile are taken by an estimated one in four UK adults, who buy them without a prescription at health food shops or online.
But doctors say while they are seen as harmless health boosters, if taken with powerful medication the combination can be dangerous. They warn of ‘life-threatening adverse drug events, prolonged hospitalisation and loss of life’.
Cancer patients have seen their drugs stop working after drinking ginseng energy drinks, transplant patients’ kidneys have been rejected after taking chamomile, and people with HIV have seen the virus levels in their blood soar after taking ginkgo supplements.
People taking blood-thinning warfarin drugs for heart problems have suffered internal bleeding after using St John’s wort and other herbal medicines. Millions of people who take cholesterolbusting statins risk severe muscle pain if they drink green tea.
The study’s authors, from the University of Stellenbosch in South Africa, said the dangers were under-reported because people often did not realise herbal remedies were to blame.
And they said the rise in obesity, diabetes and cancer meant the problem was going to get worse – because more people were taking medication, and seeking additional relief from supplements.
The authors, who based their findings on 49 case reports and two small studies of 15 cases each, said the middle-aged and elderly were the most at risk. In most cases the interactions come about because the active ingredient in the herbal remedy works on the same part of the body as the drug, meaning it either cancels it out or boosts its power.
The study, published in the British Journal of Clinical Pharmacology, comes after the Medicines and Healthcare products Regulatory Agency (MHRA) warned that St John’s wort could stop the morning-after pill from working.
Sotiris Antoniou, of the Royal Pharmaceutical Society, said: ‘If you are taking herbal medicines, you should let your doctor or pharmacist know, so they can ensure it is safe for you to take them with statins or warfarin.’
An MHRA spokesman said: ‘Prescription-only medicines are prescription-only for a reason – they are potent and their use should be supervised by a healthcare professional so your treatment can be monitored.
‘If you are taking medicines, and also taking herbal medicines, please read the patient information provided and if you have any further questions, speak to your healthcare professional.’
The herbal medicine market in the UK is worth £500 million. Since 2011, products have to be registered with the MHRA and granted a Traditional Herbal Registration before going on sale. But they do not require the same evidence as pharmaceutical drugs as to whether they actually work.