BackgroundHealth care deciders are aware of the inappropriate use of proton pump inhibitors (PPIs). To reduce inappropriate prescriptions, the Conseil du Médicament (CdM) issued a practice guideline and the Régie de l’Assurance Maladie du Quebec (RAMQ) asked prescribers to justify its use by writing a specific indication code for their patients to obtain drug coverage. ObjectivesThis study aimed to evaluate the effectiveness of the intervention by the RAMQ to reduce inappropriate PPI prescription. MethodsA cross-sectional quasi-experimental prospective study was performed in an emergency department. Patients aged 18 years or older were included in 2016 to 2017 and 2019 to 2021 in the pre- and postintervention group, respectively. The proportion of patients on PPI without an appropriate indication were identified from patient interviews and chart review. ResultsA total of 871 and 1475 patients were recruited in the pre- and postintervention groups. According to the CdM guideline, the proportion of inappropriate PPI prescription was 30.7% (n = 267) in the preintervention group and 49.1% (n = 724) in the postintervention group (P < 0.001). According to the RAMQ criteria, the proportion of inappropriate PPI prescription was of 76.1% (n = 663) and 81.4% (n = 1200) in the pre- and postintervention group, respectively (P < 0.001). ConclusionThis study highlights the ineffectiveness of the codes for PPI prescriptions in reducing inappropriate prescriptions. It seems that the obligation to write a code does not lead to a reassessment of PPI indication.