Assessing the Appropriateness of Proton Pump Inhibitor Use in Ambulatory Patients: Findings from a Single-Centre Retrospective Study

In Thailand, there is a lack of comprehensive evaluations regarding the appropriateness of prescribing proton pump inhibitors (PPIs) to outpatients.This study aimed to evaluate guideline-discordant prescribing of PPIs for therapy and prophylaxis, as well as potentially inappropriate co-prescribing of drugs interacting with omeprazole.This cross-sectional, descriptive study was conducted at a tertiary care hospital in Thailand.A prescription audit assessed the appropriateness of prescribing oral PPIs to outpatients between January 1, 2023, and December 31, 2023.The appropriateness of PPI therapy and prophylaxis, as well as drug interactions with omeprazole, was determined according to current recommendations for PPI use.The rates of potentially inappropriate use for each assessment were determined using descriptive statistics and are presented as percentages.A total of 2,099 prescriptions were included for therapy assessment, 1,263 prescriptions for prophylaxis assessment and 3,298 prescriptions for omeprazole-related drug interaction assessment.The rate of potentially inappropriate PPI therapy was 81.71%, with the most common reason being the absence of an approved indication (49.91%), followed by potentially inappropriate treatment duration (45.42%) and daily dosing (8.05%).The rate of potentially inappropriate PPI prophylaxis was 57.24%.The percentage of prescriptions that included drugs interacting with omeprazole was 5.37%.Two medications with a major level of interaction were clopidogrel (0.58%) and methotrexate (0.33%).PPIs may be prescribed inappropriately to outpatients.This study suggests that a comprehensive review of PPI prescriptions should be conducted to ensure their appropriateness and promote more rational use of PPIs.