COMPLEMENTARY THERAPIES

Herbal and complementary therapies should not be prescribed on the inpatient medicines chart. Patients should be advised that herbal and complementary therapies will not be prescribed during their hospital stay and we would request that they do not self-administer them. Should patients self-administer these therapies during their stay without their medical team's knowledge, they do so at their own risk. This should be documented in the medical notes. 

Complementary and alternative medicine (CAM) cover many beliefs and therapies. The information below relates mainly to herbal products but also covers homeopathy and dietary supplements.

Herbal products

These are made from plants and are often given orally. They can cause dose-related side effects and allergy, as well as interactions. Whether an interaction will occur or not is often difficult to determine, but some herbal products can affect cytochrome P450 enzymes, and may have side effects that are additive to a patient’s conventional medicines or oppose them.

Homeopathy products

Very, very dilute concentrations of natural substances that are unlikely to have safety implications in practice if prepared correctly. There is no evidence that homeopathic medicines interact with conventional medications. In practice, if a homeopathic medicine is from a reputable source and the strength is stated, it is generally accepted that no interaction with conventional medicines, or any adverse effects, would be anticipated based on conventional beliefs. High concentration or unknown dilution products may, theoretically, contain active ingredient and could potentially interact with conventional medicines. Such situations should be treated as if dealing with a herbal product. The NHS doesn't support the prescribing of homeopathic medicines due to lack of clinical or scientific evidence.

Dietary supplements

These are usually food constituents taken to supplement the diet such as vitamins, amino acids, and co-enzymes. They can cause side effects and sometimes interactions. Dietary supplements also have the potential to cause adverse effects and to interact with conventional and alternative medicines. Some products contain levels of vitamins or minerals in excess of those in prescription-only medicines and high doses can cause toxicity. The Food Standards Agency has set safe levels of intake for vitamins and minerals.

Regulatory control of herbal medicines in the UK

In the UK, Council Directive 2004/24/EC was adopted as the national legal regulation of herbal products. It came into full effect in 2014 after a seven year transition period that was extended by a further three years. Herbal products in the UK can therefore be granted a Traditional Herbal Registration (THR), or a Marketing Authorisation (MA), also referred to as a product license; it is no longer lawful to sell a mass produced herbal medicine without a marketing authorisation or a THR. The MHRA currently list over 350 herbal medicines that have been granted a THR (1).

However, many herbal products from health food shops or from online sources may not have a MA or granted a THR and would therefore be classed as an unlicensed product.

Quality, Safety and Efficacy of Herbal Medicines

The quality of an unregulated herbal remedy will not have been assessed by a Regulatory Authority and may thus potentially affect the safety and efficacy of the product. The majority of herbal medicinal products are only available as unlicensed products. When deciding upon the suitability of such products, a pharmacist should consider the intended use and the manufacturer. It is highly likely that unlicensed herbal remedies manufactured by an established pharmaceutical company will have been subjected to suitable in-house quality control procedures.

The use of herbal medicinal products continues to increase and there is growing evidence that herbal medicines are used widely by all groups of society including children, pregnant and breastfeeding mothers, women, especially during the menopause, and the elderly. Of particular importance is the use of herbal medicines by patients with a wide range of conditions many of whom are stabilised on prescription medicines and findings that patients are reluctant to tell their doctors about herbal products they are taking. Over recent years the significance of herb–drug interactions has been recognised and with this the realisation that healthcare professionals need to be aware that patients may be taking herbal medicinal products and need to understand their effects and be aware of the potential problems associated with their use.

Not all herbal products are medicines, some can be classed as food supplements or cosmetics and there is no guarantee that these products are of good quality or provide any health benefits.

A medicinal product can be defined as any substance or combination of substances presented as having properties for treating or preventing disease in human beings. Products that are not licensed as medicinal products should not make claims about preventing disease in humans.

The prescribing and administration of any such treatment which is classed as a medicine shall be done in accordance with the procedures described in Section 19 and Section 20.

Cannabis based products

Cannabis based products or cannabidiol or CBD oil available for purchase from health food shops, community pharmacies or other outlets are NOT medicinal cannabis and there is no guarantee that these products are of good quality or provide any health benefits and their use could be illegal depending on the tetrahydrocannabinol (THC) content. These preparations are not available via prescription.

There are licensed medicinal cannabis products available such as Sativex® and Epidyolex®, these are only prescribed for restricted, specialist indications.

Perioperative

The UK Clinical Pharmacy Association peri-operative handbook recommend that all herbal medicines should be stopped 2 weeks pre-operatively for elective surgery and to consider potential side effects and interactions if emergency surgery required.

POINTS for consideration:

What is the product and what does it contain?

Why does the patient take it?

Where did they get it from?

Is there a potential for the herbal product or other complementary therapy to interact with any prescribed medicines?

If suspected adverse effect to a herbal or homeopathic remedy or other complementary therapy - report via the MHRA Yellow Card Reporting scheme.

Useful Resources

BNF via www.medicinescomplete.com (Athens login). Has limited information on herbal products.

Herbal Medicines via www.medicinescomplete.com (Athens login). Monographs provide information on uses, dosage, pharmacological actions, evidence of efficacy, adverse effects and contraindications of herbal medicines. Limited information provided on safety in pregnancy and breastfeeding, and drug interactions.

Martindale via www.medicinescomplete.com (Athens login). Includes monographs on many herbal and complementary medicines.

Stockley's Drug Interactions via www.medicinescomplete.com (Athens login). Contains limited information on herbal drug interactions.

Specialist Pharmacy Website, www.sps.nhs.uk. Several Medicines Q&As relate to the use of herbal or complementary medicines.

Tayside Medicines Information Service - tay.medinfo@nhs.scot or 01382 632351 or extension 32351. They have access to more specialist resources.

References

1. MHRA Guidance. Herbal medicines granted a traditional herbal registration. Updated 18 December 2019. Accessible via https://www.gov.uk/government/publications/herbal-medicines-granted-a-traditional-herbal-registration-thr/herbal-medicines-granted-a-traditional-herbal-registration