Food–drug interactions in the summary of product characteristics of proprietary medicinal products

BackgroundFood–drug interactions can produce negative effects in the safety and efficacy of drug therapy, as well as in the nutritional status of the patient. However, the data commonly provided to the prescriber about possible nutrient–pharmacological compound interactions and the recommendations for their prevention are often scarce. The summary of product characteristics (SmPC) of a proprietary medicinal product, as authorised by the health authorities in Europe, is usually the main source of information for the health professional. Therefore, the SmPC can be a useful tool to prevent or reduce food–drug interactions and, as a consequence, improve the therapeutical approach.ObjectiveThe aim of this study was to assess the information about food–drug interactions with potential clinical relevance as it is described in the SmPCs of the authorised medicinal products in a European Union country (Spain).MethodsA bibliographical search of food–drug interactions, including nutrients and alcohol, was carried out. The adequate information to be included in the SmPC was defined in accordance with the European Recommendations in this field. The SmPCs of the medicinal products containing selected active substances were examined with emphasis on food–drug interactions.ResultsIt was found that, frequently, the information concerning food–drug interactions as is mentioned in the SmPC of the authorised medicinal products in Spain does not fulfil the current recommendations, both in quantity and quality. Indeed, the available data reveal that the food–drug information is only mentioned in 72.7% of all SmPC where it should be and it was only found in the specific section for interactions in 36.0% of all cases. The description and agreement with recommendations for each SmPC item ranged between 4.2% and 36.0% and between 31.8% and 49.0%, respectively. Some related factors, such as the clinical relevance of the interaction, the existence of an authorised SmPC and the registration procedure followed, influence the information characteristics concerning food–drug interactions.ConclusionThe SmPC is a suboptimal source of information for food–drug interactions.