Assessing Safety Concerns in Omeprazole Use: An Observational Study of Potentially Inappropriate Prescriptions and Patient Adherence in a Spanish Community Pharmacy

<b>Introduction:</b> Omeprazole is commonly prescribed for conditions associated with excess gastric acid, including gastroesophageal reflux and <i>Helicobacter pylori</i> infection. Spain ranks highest among Organization for Economic Co-operation and Development (OECD) countries in omeprazole consumption (measured in doses per 1000 inhabitants per day, DHD), indicating potential overuse and misuse. Community pharmacists are pivotal in collaborating with healthcare professionals to address safety risks and improve patient outcomes. <b>Objective:</b> This study aims to profile omeprazole users to inform pharmaceutical care (PC) strategies that address patient-specific needs and improve treatment safety. <b>Methods:</b> We conducted an observational, cross-sectional study (CEIm Code FCF-OME-2023-01) involving 100 omeprazole users at a community pharmacy in Barcelona from November 2023 to May 2024. Data were collected via clinical interviews using a Data Collection Questionnaire. <b>Results:</b> Among the omeprazole users, 49% were male, 51% female, and 56% were over the age of 65. A significant proportion (71%) exhibited long-term omeprazole use, and 30% were polymedicated (taking five or more medications). Notably, 52% of patients reported no history of gastric symptoms. Additionally, 22% reported using omeprazole occasionally, following short-term, on-demand treatment regimens, while 78% adhered to a chronic daily dosing schedule. Among these patients, 29.5% demonstrated poor treatment adherence. The analysis of medication-related problems (MRPs) among the 78 patients using omeprazole daily and chronically revealed that the most prevalent MRPs were “unnecessary medication”, “lack of adherence”, “wrong administration”, “drug interactions”, and “lack of knowledge regarding medication use”. Based on STOPP criteria, 45% of users were candidates for deprescribing or dose adjustment. <b>Conclusions:</b> The high incidence of MRPs among omeprazole users highlights the need for enhanced pharmaceutical care (PC). Proactive pharmacist interventions, including deprescribing, dose adjustments, and prescriber collaboration, can reduce adverse medication outcomes and promote safer omeprazole use.