Safety concerns in simultaneous use of prescription and 'over-the-counter' medicines- results of patient survey in Estonia.

Maia Gavronski,Daisy Volmer

doi:10.1186/2193-1801-3-143

Abstract

During the last decades, the share of population using prescription (Rx) medicines has considerably increased. With the wider introduction of self-medication and the use of over-the-counter (OTC) medicines, there is a real threat for drug-drug interactions between Rx and OTC medicines neither identified nor overseen by healthcare specialists.The objectives of this survey were to ascertain how often, and for what conditions OTC and Rx medicines are used simultaneously, and to discuss possible health hazards connected with the concomitant use of these medicines.This survey was designed as a descriptive, cross-sectional questionnaire-based interview which was conducted amongst pharmacy customers and patients in urban and rural areas of Estonia in between 2010–2012.In total, 712 respondents participated in the survey. Of those, 50.4% reported concomitant use of Rx and OTC medicines during the survey. The simultaneous use of Rx and OTC medicines increased with age and the number of chronic diseases (both p < 0.001). Of chronic patients, 37.1% used Rx and OTC medicines on a daily basis over a four-week period before the survey, and considering reported chronic diseases and the most widespread OTC medicines, they could encounter drug-drug interactions between Rx medicines (e.g. antihypertensives, anti-inflammatory medicines) and OTC medicines (e.g. paracetamol, NSAID-s, herbal medicines and adsorbents).The present survey revealed frequent concomitant use of Rx and OTC medicines. Especially vulnerable are chronic and elderly patients. In the future, both patients and healthcare specialists should pay more attention to possible drug-drug interactions of Rx and OTC medicines.

Highlights

The use of over-the-counter (OTC) medicines has increased significantly in recent years (Amoako et al 2003; Goh et al 2009), but despite the positive aspects, such as improved availability of medicines, decreased number of physicians’ visits for minor illnesses and self-limiting conditions, and the increase of patients involvement in their treatment, patients do not fully comprehend the risks accompanying self-treatment, such as prolonged use, wrong dosage, side effects, and possible drug-drug interactions (Eickhoff et al 2012)
Olesen et al found that in Denmark, 50% of elderly patients taking OTC medicines were exposed to potential interactions (Olesen et al 2013); and Sihvo et al described that four percent of OTC users had taken drug combinations with the potential for clinically significant interactions (Sihvo et al 2000)
It depends on the patients whether they inform their general practitioner (GP) about the use of OTC medicines, and the pharmacist about Rx medicines, and whether they receive evidence-based information concerning possible interactions (Estonian Electronic Health Record (EHR) Case Study 2013; Implementation of digital prescriptions in Estonia 2013)

Summary

Introduction

The use of over-the-counter (OTC) medicines has increased significantly in recent years (Amoako et al 2003; Goh et al 2009), but despite the positive aspects, such as improved availability of medicines, decreased number of physicians’ visits for minor illnesses and self-limiting conditions, and the increase of patients involvement in their treatment, patients do not fully comprehend the risks accompanying self-treatment, such as prolonged use, wrong dosage, side effects, and possible drug-drug interactions (Eickhoff et al 2012). Olesen et al found that in Denmark, 50% of elderly patients taking OTC medicines were exposed to potential interactions (Olesen et al 2013); and Sihvo et al described that four percent of OTC users had taken drug combinations with the potential for clinically significant interactions (Sihvo et al 2000). Based on this knowledge, it is necessary to study the frequency of and possible risks with the concomitant use of OTC and Rx medicines in more detail

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Discussion

Conclusion