Fluvoxamine for Outpatient COVID-19 to Prevent Hospitalization: A Systematic Review and Meta-Analysis
Importance: Widely available and affordable options for the outpatient management of COVID-19 are needed, particularly therapies that prevent hospitalization. Objective: Perform a meta-analysis of the available randomized clinical trial evidence for fluvoxamine in the outpatient management of COVID-19. Data Sources: World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov. Study Selection: Completed outpatient trials with available results which compared fluvoxamine to placebo. Data Extraction and Synthesis: We followed the PRISMA 2020 guidelines. We extracted study details in terms of inclusion criteria, trial demographics and the pre-specified outcome of all-cause hospitalization. Risk of bias was assessed by the Cochrane Risk of Bias 2 tool. We conducted a frequentist random effects meta-analysis, as well as two sensitivity analyses using a Bayesian random effects meta-analysis with different estimates of prior probability: a weakly neutral prior (50% chance of efficacy with 95% confidence interval for Risk Ratio [RR] between 0.5 and 2) and a moderately optimistic prior (85% chance of efficacy). We contextualized the results by estimating the probability of any effect (RR ≤1) and moderate effect (RR ≤0.9) on reducing hospitalization. Main Outcome(s) and Measure(s): All cause hospitalization. Results: 2196 participants were included from 3 identified trials. The risk ratios for hospitalization were 0.75 (95%CI, 0.57-0.97) for the frequentist analysis, 0.78 (95%CI 0.58-1.08) for the Bayesian weakly neutral prior, and 0.73 (95%CI, 0.53-1.01) for the Bayesian moderately optimistic prior. Depending on the scenario, the probability of any effect on hospitalization ranged from 94.1% to 98.3% and a moderate effect from 81.6% to 91.1%. Conclusions and Relevance: Under a variety of assumptions, fluvoxamine shows a high probability of preventing hospitalization in outpatients with COVID-19. While ongoing randomized trials are important to evaluate alternative doses, explore the effectiveness in vaccinated patients, and provide further refinement to these estimates, fluvoxamine could be recommended as a treatment option, particularly in resource-limited settings or persons without access to SARS-CoV-2 monoclonal antibody therapy or direct antivirals.