The paper suggests that patients are neither sufficiently informed nor aware about the potential impact of these compounds on the laboratory test results and as a result may not feel it necessary to disclose their use.
“We hope that our survey helps to raise awareness about this need to educate patients about the potential effect of OTC drugs and dietary supplements on lab test results,” said Professor Ana-Maria Simundic of the Sveti Duh Clinical Hospital in Zagreb, Croatia, and the corresponding author of the article.
“We would encourage clinicians and lab staff to engage more with their patients and ask them direct questions about the use of various self-prescribed products."
The study, published in association with the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM), believes the high prevalence of their use are an easily overlooked fact.
According to German Federal Health Reporting, OTC self-medication in Germany in 2006 represented a market with an annual sale of over €5.4 bn.
Meanwhile, the annual expenditure in US on more than 85,000 different combinations of vitamins, minerals, botanicals, amino acids, probiotics and other supplement ingredients rose to nearly $32bn (€28bn).
OTC and supplement use
In a survey of 200 patients in 18 European countries, 68% of patients regularly took at least one OTC drug or dietary supplement.
The frequency of patients consuming at least one OTC drug or dietary supplement differed between countries.
Vitamins (38%), minerals (34%), cranberry juice (20%), acetylsalicylic acid (ASA) (17%) and omega fatty acids (17%) were the most commonly used in the study.
Countries with the highest overall rate of consumption of individual OTC products and dietary supplements were Turkey, Russia, Hungary and Croatia.
Slovenia, Austria and Portugal had the lowest frequency of OTC and dietary supplements use among the surveyed populations.
Additionally, there was a ten-fold or even greater difference between the frequency of the use of some individual OTC products and dietary supplements (e.g. 3% vs. 60.5% for ASA, 1.5% vs. 36% for weight loss products, in Slovenia and Turkey, respectively) between Slovenia and Turkey.
Although more data is needed about the frequency of the consumption of various dietary products, vitamins or OTC drugs, the authors believe educational intervention, which target healthcare professionals and patients is necessary to highlight the issue.
“Clinicians ordering the tests and laboratory staff should be more engaged with patients by asking them direct questions about the use of various self-prescribed products,” the authors suggested.
“A standardised questionnaire to be fulfilled before phlebotomy, regarding some most frequent preanalytical factors (including OTC products) which influence laboratory test results, could be one good solution,” they added.
The authors also call upon regulatory agencies to implement tougher rules for the approval of OTC products and include a list of potential side effects as well as list of potential laboratory abnormalities.
“New compounds surface every day, and the number of new tests is also increasing. As stated clearly earlier in the discussion, the number of different compounds to interact with the test results are vast,” they said
“So, how do we keep up our knowledge on this? One potential solution might be an international OTC library, which may be interconnected with our laboratory information systems.”
However, Patrick Coppens, the director for regulatory & scientific affairs at Food Supplements Europe disagreed with these findings saying, “We do not think regulations can play a role”.
“The contact between a person and his doctor should be one of trust and it is the role of a medical professional to ask the patient all relevant information that is of relevance for making a correct diagnosis.”
“We note that the study shows that a majority of people are aware and do inform their medical professionals,” he added.
“There may be many reasons for patients not disclosing the use of their supplements. As the paper indicates this may include failure to see the relevance or also reluctance, given the generally negative attitude towards food supplements of medical professions.”
Source: Clinical Chemistry and Laboratory Medicine (CCLM)
Published online ahead of print: doi.org/10.1515/cclm-2018-0579
“Patient’s knowledge and awareness about the effect of the over-the-counter (OTC) drugs and dietary supplements on laboratory test results: a survey in 18 European countries.”
Authors: Ana-Maria Simundic et al