Adverse events to food supplements containing red yeast rice: comparative analysis of FAERS and CAERS reporting systems

Introduction: Food supplements containing red yeast rice (RYR) are proposed as an alternative in statin-intolerant patients, although they actually contain natural statin(s) and their safety in clinical practice is still incompletely characterized. We described and compared adverse events (AEs) associated with RYR products submitted to reporting systems maintained by the Food and Drug Administration (FDA), with a focus on liver and muscular events. Methods: We extracted RYR-related AEs from the FDA Adverse Event Reporting System (FAERS) [first quarter (Q1)-2004 to Q2-2016], a drug-based archive, and the Center for Food Safety and Applied Nutrition Adverse Event Reporting System (CAERS) (Q1-2004 to Q1-2017). Disproportionality via reporting odds ratio (ROR) with 95% confidence interval (CI) calculation and case-by-case inspection were performed, with a focus on muscular and hepatic AEs. Results: One thousand three hundred AEs were extracted from FAERS (RYR mainly reported as a concomitant agent), whereas only 159 AEs were found in CAERS (RYR recorded mainly as a suspect agent). In FAERS, a large number of reports emerged for “general disorders and administration site conditions,” whereas CAERS received also a high number of reports for “investigations” and “musculoskeletal and connective tissue disorders”. Disproportionality analyses confirmed higher reporting of serious muscular and liver injuries: in FAERS, five cases of hepatic disorders (ROR = 13.71; 95% CI 5.44–34.57); in CAERS, 27 cases of rhabdomyolysis/myopathy (8.44; 5.44–13.10). Conclusions: Notwithstanding recognized limitations, these findings strengthen the importance of exploring multiple databases in safety assessment of RYR products, which should be monitored by clinicians for muscular and hepatic safety, and call for urgent review by policymakers to harmonize their regulatory status.