Complementary products: resources to support answering questions

Access

Free to access through Drugs.com. Register to access saved searches function.

Overview

Aimed at both healthcare professionals and the public so select the professional tab when viewing interaction information.

A separate section on Natural Product Information is available for healthcare professionals.

Considerations

• Drug interaction checker includes conventional medicines, complementary products, food and alcohol interactions.
• Multiple products and medicines can be added to the drug interaction checker.
• Caution is required when interpreting the interaction information as the database extrapolates by therapeutic class.
• Individual Summary of Product Characteristics (SmPC) should be checked to understand the pharmacokinetics of conventional medicine.
• Interaction monographs provide monitoring and management advice for single interactions.
• Monographs are fully referenced.

The Natural Product Information section provide monographs for complementary ingredients which include:

• dosing guidelines
• interactions information
• side effects
• contraindications
• safety assessments
• efficacy assessments

UK relevance

• A USA resource so brand names, conventional medicines and combination medicines may not match those licensed in the UK.
• UK and USA brand names may differ in ingredients.
• Dosing reflects USA practice and may differ from UK labels.

Access

The herbal products section is free to access through Memorial Sloan Kettering Cancer Center.

Overview

A specialist cancer research hospital based in the USA providing public focused herbal product monographs.

The monographs can be searched by herbal product or ingredient.

Each monograph includes 2 sections: one for the public and caregivers, and another for healthcare professionals.

Considerations

• Herbal monographs provide information on USA brand names, a list of suggested uses, contraindications, side effects, and a section on interactions.
• Interactions are usually classed by metabolic path such as cytochrome P450, P3A, P1A2, and p-glycoprotein.
• Individual SmPC should be checked to understand the pharmacokinetics of conventional medicine.
• Monographs are fully referenced.

UK relevance

• A USA resource so brand names, conventional medicines and combination medicines may not match those licensed in the UK.
• UK and USA brand names may differ in ingredients.
• Dosing reflects USA practice and may differ from UK labels.

Access

Free access to the herbs, supplements and vitamin section through www.mayoclinic.org/drugs-supplements.

Overview

A searchable database of monographs though not as exhaustive as Drugs.com or the Memorial Sloan Kettering Cancer Center herbal section.

The monographs are aimed at the public.

Considerations

• Monographs provide information on uses and dosing based on what the evidence suggests.
• Be cautious with product uses as the monographs are not fully referenced.
• A reference list is provided at the end of each monograph.
• Monographs provide common interactions with therapeutic classes of conventional medicines such as antidepressants.
• Interactions are listed by metabolic pathway for the conventional medicine such as cytochrome P450 1A2.
• Individual SmPC should be checked to understand the pharmacokinetics of conventional medicine.

The monographs carry Mayo Clinic recommendations regarding the complementary product claims. There are 3 types of recommendations:

• generally safe means some research has shown the complementary product to do what it claims for the indication stated and at the dose stated
• caution means that there may be a lack of research to show the product is effective or the product may be effective, but it carries a high risk of side effects
• avoid means that there is either no research to show the products benefits, the risk from taking the product is too high or both

UK relevance

• A USA resource so brand names, conventional medicines and combination medicines may not match those licensed in the UK.
• UK and USA brand names may differ in ingredients.
• Dosing reflects USA practice and may differ from UK labels.

Access

Part of the NatMed resource range and accessible by paid subscription through NatMed Pro.

Overview

NatMed Pro hosts several tools including an interactions checker for potential interactions between complementary products and conventional medicines.

Other tools include:

• searching a condition to find an effective complementary product
• safety of complementary products in pregnancy and breastfeeding
• identifying if a complementary product could be the cause of a specific side effect

Considerations

• Interaction tool allows selection of a single complementary ingredient or a multi-ingredient complementary product.
• Interaction tool only screens for interactions between conventional medicines and complementary products.
• Resulting interactions are ordered from major to minor.
• Caution is required when interpreting the information provided as it may be an extrapolation based on cytochrome P450 substrate.
• Individual SmPC should be checked to understand the pharmacokinetics of conventional medicine.

UK relevance

• A USA resource so brand names, conventional medicines and combination medicines may not match those licensed in the UK.
• UK and USA brand names may differ in ingredients.
• The interaction tool has a preference to map complementary products and conventional medicines to US brands which can result in the incorrect UK ingredients being searched.
• Dosing reflects USA practice and may differ from UK labels.

Access

Free access to full content through BNF (adults) and cBNF (children).

Overview

The scope of the BNF and BNFc is restricted to conventional medicines.

References to complementary ingredients are made if they affect conventional therapy.

A few herbal ingredients are mentioned such as echinacea, ginkgo biloba, ginseng, garlic, kava kava, and St John’s Wort.

Aimed at Healthcare Professionals and contains NHS treatment summaries.

Considerations

• Use the interactions search to find herbal ingredient specific information.
• Information on herbal interactions may not be comprehensive due to the BNF stating a restricted scope.
• No monographs for herbal ingredients.
• Advice on how to report suspected side effects from complementary, herbal and homeopathic products.
• Highlights the need to stop herbal medicines prior to surgery. See our pre-operative stopping advice in the SPS article Managing complementary products and conventional medicines (SPS page).

UK relevance

The BNF is jointly published by the British Medical Journal (BMJ) and the UK Royal Pharmaceutical Society (RPS).

The BNFc is jointly published by the BMJ, the RPS and the Royal College of Paediatrics and Child Health (RCPCH).

Access

Paid subscription through Medicines Complete.

Overview

Evidence based guidance on the interactions of herbal ingredients with conventional medicines, dietary supplements and nutraceuticals.

Considerations

• Interaction tool allows multiple conventional medicines and herbal ingredients to be checked simultaneously.
• Information on practical actions, interaction severity and the type of evidence base.

Stockley’s reviews the evidence base for the interaction information. There are 5 types of recommendations:

• avoid for a life threatening or serious interaction
• monitor or adjust for a significant hazard where a dose adjustment is needed or monitoring advised
• uncertain for potentially hazardous interactions but data is poor or inconclusive
• inform or monitor for uncertain interaction outcomes
• no action needed when no clinically significant interaction is expected

UK relevance

Published by the UK based Pharmaceutical Press and is comprehensive for UK conventional medicines and complementary ingredients.