The efficacy and safety of hydroxychloroquine for COVID-19 prophylaxis and clinical assessment: an updated meta-analysis of randomized trials

Background: Coronavirus disease 2019 (COVID-19), a disease that affected tens of millions of people, upended the lives of countless individuals around the globe. The chloroquine (CQ) and its analogue hydroxychloroquine (HCQ) were the most frequently cited as potential treatments and preventatives against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The primary aim of this investigation was to scrutinize the effectiveness and safety of HCQ for COVID-19 prevention and to present powerful evidence and reference for clinical practice. Methods: PubMed, Ovid and the Cochrane COVID-19 Register of Controlled Trials (CENTRAL) were systematically searched from inception to January 31, 2022. Randomized controlled trials (RCTs) trials that included participants who were SARS-CoV-2 negative at the time of registration were enrolled in this metaanalysis. The intervention group took HCQ or CQ orally. The control group was not blinded by quinine or placebo. Pooled relative risk (RR) of SARS-CoV-2 infection, mortality, hospitalization, adverse events, and compliance were calculated. The software tools utilized for statistical analyses were Stata 14 and Review Manager 5.3. Results: A total of 9 studies including 7,825 participants were enrolled. Bias of individual studies were assessed as low risk. The pooled RR for SARS-CoV-2 infection was 0.75 [95% confidence interval (CI): 0.68-0.83] (z=-4.01, P<0.0001; I-2=11%). The pooled RR for hospitalization was 0.72 (95% CI: 0.35-1.50) (z=0.87, P=0.39; I-2=0.0%). The pooled RR for mortality and adverse events were 3.26 (95% CI: 0.13-79.74) (z=0.72, P=0.47; I-2=0.0%) and 1.90 (95% CI: 1.20-3.02) (z=2.73, P=0.0063; I-2=94%). Conclusions: Results of this meta-analysis indicated significant impact of HCQ on SARS-CoV-2 infection with higher risk of adverse events. These findings must be considered with caution, and further research is necessary to delineate the specific circumstances where HCQ may be effective for COVID-19 prevention.