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Chinese herb Aconite (monkshood) warning

Concerns over potentially toxic Chinese herbal medicine
WebMD UK Health News
Medically Reviewed by Dr Farah Ahmed

18th April 2013 - The medicines regulator, the MHRA, is warning people not to use the Chinese herbal medicine Zheng Tian Wan, used to treat migraines, as it contains a potentially toxic herbal ingredient.

Zheng Tian Wan pills contain Aconite, a poisonous plant toxic to the heart and the nervous system and linked to serious health complications including death.

The product is an unlicensed herbal medicine which means it has not been assessed for safety and quality by the MHRA. It came to the agency's attention as a result of being supplied to a patient by a herbal practitioner.


Aconite is a plant which contains a strong, fast-acting poison. The root is used as medicine. Aconite is known by a number of different names, including monkshood and is on a UK list of restricted herbal ingredients.

It should not be used in unlicensed products for oral use and herbal practitioners in the UK should only use aconite in preparations for external use only on unbroken skin.

It can be prescribed in oral medicines by a qualified medical doctor under supervision as a prescription-only medicine.

Aconite root contains chemicals that may improve circulation but it also contains chemicals that can seriously harm the heart, muscles and nerves. It can cause nausea, vomiting, weakness, sweating, breathing and heart problems. The MHRA has previously received three reports of suspected side effects to aconite, one where a patient suffered kidney problems, a second person was hospitalised after suffering dizziness and 'pins and needles' (paraesthesia) and the third experienced palpitations, aches and pains with shortness of breath but recovered after stopping taking the product.

Andrea Farmer, Herbal Policy Manager at the MHRA says in a press release: "Herbal medicines can have a very significant effect on the body. In certain circumstances, such as with aconite taken orally, they can be extremely dangerous.

"Products intended for oral use containing aconite are not permitted in the UK without appropriate authorisation.

"If you have taken Zheng Tian Wan or any other aconite -containing product, speak to your GP or healthcare professional as soon as possible."

Natural not necessarily safe

The MHRA says while many herbal remedies are reasonably safe, it is important to remember that because a product contains natural ingredients this doesn't guarantee it is safe. It recommends you always consult with a pharmacist or doctor to make sure that a herbal remedy is suitable to take and will not interact with any other medicines you may be taking.

Andrea Farmer says: "Natural does not mean safe. To help you choose an herbal medicine that is suitable for you, look for a product that has a Traditional Herbal Registration (THR) or product license number on the packaging. These products have met the acceptable quality and safety standards.

"And if you think you have suffered a side effect to an herbal medicine, please tell us about it through our Yellow Card Scheme."

Reviewed on April 18, 2013

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