A Systematic Review and Meta-Analysis of the Safety of Hydroxychloroquine in a Randomized Controlled Trial and Observational Studies

Introduction: Hydroxychloroquine (HCQ) has recently become the focus of attention in the current COVID-19 pandemic. With an increase in the off-label use of HCQ, concern for the safety of HCQ has been raised. We, therefore, performed this systematic review to analyze the safety data of HCQ against placebo and active treatment in various disease conditions. Methods: We searched PubMed, Embase, and Cochrane for Randomized Controlled Trials (RCTs) and Observational Studies (OSs) that evaluated HCQ for the treatment of any disease other than COVID19 in adult patients up to May 2020. We assessed the quality of the included studies using Risk of Bias 2 (for RCTs) and Newcastle-Ottawa Scale (for OSs). Data were analyzed with random-effect meta-analysis. Sensitivity and subgroup analyses were performed to identify heterogeneity. Results: A total of 6641 studies were screened, and 49 studies (40 RCTs and 9 OSs) with a total sample size of 35044 patients were included. The use of HCQ was associated with higher risks of TDAEs as compared to placebo/no active treatment [RR 1.47, 95%CI 1.03-2.08]. When HCQ was compared with active treatments, the risks of AEs [RR 0.74, 95% CI 0.63-0.86] and TDAEs were less in the HCQ arm [RR 0.57, 95% CI 0.39-0.81]. The outcomes did not differ in the sensitivity analysis. Conclusion: The results suggest that the use of HCQ was associated with a lower risk of AEs and TDAEs as compared to active treatment, whereas posing higher risk of TDAEs as compared to placebo.