ABSTRACT
Introduction: No early treatment intervention for COVID-19 has proven effective to date. We systematically reviewed the efficacy of hydroxychloroquine as early treatment for COVID-19. Material and methods: Randomized controlled trials (RCTs) evaluating hydroxychloroquine for early treatment of COVID-19 were searched in five engines and preprint websites until September 14, 2021. Primary outcomes were hospitalization and all-cause mortality. Secondary outcomes included COVID-19 symptom resolution, viral clearance, and adverse events. Inverse variance random-effects meta-analyses were performed and quality of evidence (QoE) per outcome was assessed with GRADE methods. Results: Five RCTs (n = 1848) were included. The comparator was placebo in four RCTs and usual care in one RCT. The RCTs used hydroxychloroquine total doses between 1,600 and 4,400 mg and had follow-up times between 14 and 90 days. Compared to the controls, early treatment with hydroxychloroquine did not reduce hospitalizations (RR = 0.80, 95% CI: 0.47-1.36, I 2 = 2%, 5 RCTs, low QoE), all-cause mortality (RR = 0.77, 95% CI: 0.16-3.68, I 2 = 0%, 5 RCTs, very low QoE), symptom resolution (RR = 0.94, 95% CI: 0.77-1.16, I 2 = 71%, 3 RCTs, low QoE) or viral clearance at 14 days (RR = 1.02, 95% CI: 0.82-1.27, I 2 = 65%, 2 RCTs, low QoE). There was a larger non-significant increase of adverse events with hydroxychloroquine vs. controls (RR = 2.17, 95% CI: 0.86-5.45, I 2 = 92%, 5 RCTs, very low QoE). Conclusions: Hydroxychloroquine was not efficacious as early treatment for COVID-19 infections in RCTs with low to very low quality of evidence for all outcomes. More RCTs are needed to elucidate the efficacy of hydroxychloroquine as early treatment intervention.
ABSTRACT
There are no proven prophylactic interventions for COVID-19. We systematically reviewed the efficacy of prophylactic hydroxychloroquine for COVID-19. Studies evaluating hydroxychloroquine for prophylaxis of COVID-19 were searched in several engines until 8 December 2020. Primary outcomes included RT-PCR positivity, COVID-19 infections (positive RT-PCR or compatible COVID-19 symptoms), and all-cause mortality. Random effects meta-analyses were performed for all outcomes. Five randomized controlled trials (RCTs) (n = 5579) and one cohort (n = 106) were included. Placebo was the comparator in four RCTs, and usual care in one RCT. Compared to the controls, five RCTs showed that hydroxychloroquine prophylaxis did not reduce RT-PCR positivity (RR 1.01, 95% CI 0.88-1.16), COVID-19 infection (RR 0.98, 95% CI 0.78-1.22), or all-cause mortality (RR 0.73, 95% CI 0.27-1.99). There were no differences of effects by pre- or post-exposure prophylaxis. Prophylaxis with hydroxychloroquine increased the risk of diarrhea, abdominal pain, or vomiting (RR 4.56, 95% CI 1.58-13.19). There were no effects of hydroxychloroquine on other secondary outcomes. Quality of evidence was low to very low for all outcomes. Hydroxychloroquine was not efficacious as a prophylaxis for COVID-19 infections, defined either as RT-PCR positivity or as a composite of RT-PCR positivity or compatible symptoms. Hydroxychloroquine did not reduce all-cause mortality, clinical worsening, or adverse events.