Muscular Adverse Drug Reactions Associated with Proton Pump Inhibitors: A Disproportionality Analysis Using the Italian National Network of Pharmacovigilance Database

Introduction: Proton pump inhibitors (PPIs) have been implicated in the occurrence of moderate to severe myopathies in several case reports. Aim: This study was performed to assess the reporting risk of muscular adverse drug reactions (ADRs) associated with PPIs in the Italian National Network of Pharmacovigilance database. Methods: A disproportionality analysis (case/non-case) was performed using spontaneous reports collected in the database between July 1983 and May 2016. Reporting odds ratio (ROR) and 95% confidence intervals (CIs) were calculated as a measure of disproportionality. In a secondary and tertiary analysis, we explored the association of PPIs with muscular ADRs after taking into account the masking effect of statins. Moreover, the possibility of an interaction between PPIs and statins, leading to the occurrence of muscular ADRs, was also tested. Results: The study was carried out on 274,108 reports. The ROR of muscular ADRs for PPIs, adjusted for age and gender, was 1.484 (95% CI 1.204–1.829; p