Published in BMC Primary Care, the new research highlights the potential dangers of drug/supplement interactions. It also states that 60% of the GPs surveyed were willing to deprescribe at least one supplement their patients were using without their knowledge.
Among the study group of older patients with polypharmacy, 70% reported taking at least one supplement, and the main reason was general health, followed by muscle, joint or bone health.
Vitamins and minerals were the most commonly used supplements, specifically vitamin D, magnesium and vitamin B12, which are covered by mandatory health insurance in Switzerland when prescribed by a physician.
In line with previous studies, respondents reported a lack of knowledge about dietary supplements, including their risks and benefits. The survey also revealed discrepancies between the number of medications and supplements reported by GPs and patients.
“The finding that many supplements are not disclosed reinforces the fact that GPs should actively ask their patients about their use of dietary supplements including non-prescription ones, so that they can identify potential risks, drug-supplement and supplement-disease interactions, and lack of indications,” the researchers wrote.
Most of the older patients were unwilling to have any supplements deprescribed, which the authors noted aligns with a previous study. They said this may be due to patients' positive attitudes towards supplements and an overall lack of information about them.
Using supplements with medication
According to a 2022 IPSOS consumer survey commissioned by Food Supplements Europe, almost nine in ten Europeans had used a food supplement at some point in their lives, and the majority (93%) had used one in the last 12 months.
Additionally, although 81% of Europeans said that having a trusted recommendation was important to them, only 40% of those surveyed used medical professionals to provide their information, and 67% used labels to find out potential side effects and drug interactions.
Some supplements can increase or decrease the effects of medications that doctors have prescribed, potentially causing adverse reactions.
Experts advise that some medication and supplement interactions may be serious. For example, people taking medications with a narrow therapeutic range, such as warfarin and cyclosporine, need the right levels of these drugs to prevent reactions that may be life-threatening. Additionally, dietary supplements may cause problems during surgery, such as increasing the risk of bleeding.
“It is important to note that dietary supplements are important for vulnerable groups at risk for nutritional deficiency, but their use should be individualized and accompanied by a GP, pharmacist, dietitian or other healthcare professional to avoid interactions and adverse events,” the current study’s authors wrote.
Study details
The cross-sectional study was part of the “Understanding older patients’ willingness to have medications deprescribed in primary care” study.
Researchers asked 10 GPs in Swiss primary care to recruit a sample of 5 to 10 patients aged 65 or older taking five or more long-term medications. The GPs and their patients completed a survey about supplement use and attitudes towards deprescribing.
The analysis showed that in 60% of patients, GPs were unaware of at least one supplement used. Only 8% of patients and 60% of GPs reported at least one supplement they would be willing to deprescribe, and none of these supplements reported by GPs and patients matched.
The study concludes that GPs need to be educated to actively ask their patients about supplement use when considering their medication.
Source: BMC Prim. Care 25, 359 (2024)
doi: 10.1186/s12875-024-02605-z
“Exploring GP and patient attitudes towards the use and deprescribing of dietary supplements: a survey study in Switzerland.”
Authors: R.V. Lüthold et al.