Safety profile of chloroquine and hydroxychloroquine: a disproportionality analysis of the FDA Adverse Event Reporting System database

OBJECTIVE: The present study aims to identify potential safety signals of chloroquine (CQ) and hydroxychloroquine (HCQ), over the period preceding their repurpose as COVID-19 treatment options, through the analysis of safety data retrieved from the FDA Adverse Event Reporting System (FAERS) pharmacovigilance database.

MATERIALS AND METHODS: We performed a disproportionality analysis of FAERS data between the first quarter of 2004 and December 2019 using the OpenVigil2.1-MedDRA software. Disproportionality was quantified using the reporting odds ratio (ROR) and its 95% confidence interval (CIs). The reported mortality of CQ and HCQ was also investigated.

RESULTS: The dataset contained 6,635,356 reports. Comparison of the RORs revealed significant differences between CQ and HCQ for the following adverse events: cardiomyopathy, cardiac arrhythmias, retinal disorders, corneal disorders, hearing disorders, headache, hepatic disorders, severe cutaneous reactions, musculoskeletal disorders, and cytopenia. Only CQ was associated with psychotic disorders, suicide, self-injury, convulsions, peripheral neuropathy, and decreased appetite. In multivariable logistic regression, death was more frequently associated with CQ use, advanced age, male sex, co-reported suicide and self-injury, cardiomyopathy, cardiac arrhythmias, and decreased appetite.

CONCLUSIONS: Our results confirm previously published evidence and suggest that HCQ has a safer clinical profile compared to CQ, and thus could serve as the drug of choice for future therapeutic purposes.