Prescribers have been reminded to routinely ask people about their use of herbal medicines and dietary supplements that could interact with prescription medications.
New research has found that concurrent use of non-prescription and medication and prescribed drugs may be higher than previously thought, and a third of older people, already taking multiple medications because of comorbidity, are also taking alternative medicines.
The study, carried out in two general practices in southeast England found that 43% of female patients and 23% of men were taking herbal remedies and supplements – and some patients were taking as many as eight different alternative agents.
Substances with potential drug interaction risks include common remedies such as evening primrose oil, St John’s wort, and ginkgo. Supplements with potential interactions include glucosamine and Omega3 fish oil. The health consequences of these interactions include alterations in the concentration or effects of drugs such as treatments for hypertension, statins, and aspirin, and the most hazardous outcomes are related to increased blood glucose concentration, risk of bleeding, and reducing the effectiveness of a prescription drug.
The author, Taofikat Agbabiaka, a PhD student at the University of Hertfordshire, says: ‘This study has highlighted potential interactions from common herbal and dietary supplements used with prescribed medicines. Considering that up to a third of older adults use herbal medicines and/or dietary supplements with prescribed drugs, it is important that healthcare professionals routinely ask questions regarding the use of non-prescribed medications.’
Agbabiaka T. Br J Gen Pract 2018;68(675):e711-717