Comparisons of adverse event reporting for colistin versus polymyxin B using the US Food and Drug Administration Adverse Event Reporting System (FAERS)

Background: The polymyxins (colistin and polymyxin B) have recently reemerged in clinical practice. With the same antimicrobial activities, colistin has been more frequently prescribed in most countries, although available evidence on their nephrotoxicity is conflicting.Methods: The US Food and Drug Administration Adverse Event Reporting System (FAERS) data from Q1-2004 to Q1-2020 were used to identify adverse events (AE) reports. We described the reporting patterns and compare the reporting rates of serious AEs, acute kidney diseases (AKD), and death between colistin and polymyxin B using reporting odds ratios (RORs).Results: The annual number of AE reports increased over time for both drugs. Heterogeneity in reporting characteristics was observed in age and reporter region. RORs of serious, AKD, and death AEs were significantly higher for both drugs versus other drugs. RORs of serious and AKD AEs were higher for colistin compared to polymyxin B (p = 0.0479 and p = 0.0306, respectively), but no difference in death RORs was detected (p = 0.2211).Conclusions: This study showed higher reporting rates of serious AEs and AKD for colistin than polymyxin B, but no difference in death. The findings support future research with stronger study design and larger sample size for the safety comparison between colistin and polymyxin B.