When Characteristics of Clinical Trials Require Per-Protocol as Well as Intention-to-Treat Outcomes to Draw Reliable Conclusions: Three Examples.

Under exceptional circumstances, including high rates of protocol non-compliance, per-protocol (PP) analysis can better indicate the real-world benefits of a medical intervention than intention-to-treat (ITT) analysis. Exemplifying this, the first randomized clinical trial (RCT) considered found that colonoscopy screenings were marginally beneficial, based upon ITT analysis, with only 42% of the intervention group actually undergoing the procedure. However, the study authors themselves concluded that the medical efficacy of that screening was a 50% reduction in colorectal cancer deaths among that 42% PP group. The second RCT found a ten-fold reduction in mortality for a COVID-19 treatment drug vs. placebo by PP analysis, but only a minor benefit by ITT analysis. The third RCT, conducted as an arm of the same platform trial as the second RCT, tested another COVID-19 treatment drug and reported no significant benefit by ITT analysis. Inconsistencies and irregularities in the reporting of protocol compliance for this study required consideration of PP outcomes for deaths and hospitalizations, yet the study coauthors refused to disclose them, instead directing inquiring scientists to a data repository which never held the study's data. These three RCTs illustrate conditions under which PP outcomes may differ significantly from ITT outcomes and the need for data transparency when these reported or indicated discrepancies arise.

Fluvoxamine with bromhexine combination to prevent clinical deterioration in SARS-CoV-2

Introduction/Aim: We conducted an open label, randomized, controlled trial to assess whether fluvoxamine combined with bromhexine, given during mild to moderate SARS-CoV-2 illness, prevented clinical deterioration due to their proposed immune modulatory effects. Method(s): Participants had confirmed SARS-CoV-2 infection, experiencing mild to moderate symptoms and oxygen saturation of >=92%. Participants were randomly assigned to receive fluvoxamine (100 mg days 1 and 2, followed by 150 mg daily till day 14) with bromhexine (FLU/BRO) (16 mg daily till day 10) or favipiravir alone (FAV) (3600 mg day 1 followed by 1600 mg daily till day 5). Primary outcome was clinical deterioration within 30 days of randomization defined as shortness of breath or hospitalization for shortness of breath or pneumonia and oxygen saturation >=92%, on room air or need for supplemental oxygen to achieve oxygen saturation of >=92%. Result(s): 158 participants were randomized (average age 50 years (range 18-68 years);68 [43%] women), and 142 (89%) completed the trial. 0/78 participants experience clinical deterioration with FLU/BRO and 18/64 patients with FAV. TNF-alpha, IL-6 IL-8 and IL-1beta levels were significantly (p < 0.005) reduced with FLU/BRO compared to FAV at day 3, 5, 7 and 14. 0/78 participants had long COVID symptoms with FLU/BRO compared to 32/64 (50%) with FAV (p < 0.005). One serious (clumsiness or unsteadiness) and 10 other adverse events were reported with FLU/BRO compared to 5 serious and 12 other adverse events with FAV. Conclusion(s): Results suggest there was significantly less clinical deterioration in symptomatic COVID-19 participants treated with FLU/BRO.

METFORMIN REDUCED SARS-CoV-2 VIRAL LOAD IN A PHASE 3 RANDOMIZED CLINICAL TRIAL

Background: Metformin has in vitro activity against SARS-CoV-2. In a published phase 3, quadruple-blinded, placebo-controlled randomized trial of outpatient COVID-19 therapy, metformin resulted in a 42% reduction in ER visits/hospitalizations/deaths by day 14, 58% reduction in hospitalizations/ death by day 28, and 42% reduction in Long Covid through 10 months. This analysis presents the results of viral load sampling performed during that clinical trial. Method(s): Covid-Out trial (NCT04510194) enrolled adults aged 30 to 85 within 3 days of a documented SARS-CoV-2 infection and < 7 days after symptom onset. The trial randomized 1323 participants to metformin (1000mg/day days 2-5;1500mg/day days 6 to 14), ivermectin, fluvoxamine, and/or exact-matching placebo in a 2x3 factorial trial design. Nasal swabs for viral load were an optional component, self-collected from the anterior nares on day 1, 5, and 10. Viral loads were measured via RT-qPCR using N1 and N2 targets in the SARSCoV- 2 nucleocapsid protein, with relative Ct values converted to absolute copy number via calibration to droplet digital PCR. A linear Tobit regression model was used to assess change over time while accounting for left censoring due to the viral load limit of detection. Results were adjusted for other treatment allocations within the factorial design, vaccination status, and baseline viral load. Repeated measures were accounted for using clustered standard errors within participants. Result(s): Samples were available from n = 945, 871, and 775 participants on days 1, 5, and 10, respectively. The mean change from baseline to followup was -0.64 log10 copies/mL (95%CI, -1.16 to -0.13) for metformin versus placebo, which equates to a 4.4-fold greater decrease. The mean change in SARS-CoV-2 from baseline to day 5 was -0.48 log10 copies/mL, and was -0.81 log10 copies/mL from baseline to day 10. The anti-viral effect increased with increased metformin dosing days 6-14. The antiviral effect was larger in those unvaccinated (mean -0.95 log copies/mL) than vaccinated (mean -0.39 log copies/mL). There was no change in viral load vs. placebo for ivermectin or fluvoxamine. Conclusion(s): Metformin lowered SARS-CoV-2 viral load in this quadrupleblinded, randomized clinical trial. The temporal relationship to dose titration suggests a dose-dependent effect. The magnitude of antiviral effect was similar to nirmatrelvir at day 5, greater than nirmatrelvir at day 10. Metformin is safe, widely available, and has few contraindications.

Metformin prevents the diagnosis of Long Covid in phase 3 trial of early treatment

OBJECTIVES/GOALS: Chronic or new symptoms after infection with severe-acute-respiratory-coronavirus-2 (SARS-CoV-2) has been termed post-acute sequelae of Covid-19 (PASC) or Long Covid. Our objective is to present results from COVID-OUT, a phase 3 double-blind, randomized controlled trial of early outpatient treatment of Covid-19 with repurposed medications. METHODS/STUDY POPULATION: COVID-OUT enrolled adults age 30 to 85 with overweight or obesity who had proof of SARS-CoV-2 infection and fewer than 7 days of symptoms. In this 2 by 3 factorial design trial of metformin, ivermectin, fluvoxamine, or exact-matching placebo of each medication, participants were randomized 1:1:1:1:1:1 to the 6 treatment allocations. This focuses on whether early treatment with metformin prevented Long Covid. Immediate release metformin was titrated to 1500mg daily over the first 6 days. We assessed the incidence of clinician-diagnosed Long Covid with follow up through 10 months after enrollment. We also assessed where participants were diagnosed with Long Covid, and where they received Long Covid treatment. RESULTS/ANTICIPATED RESULTS: Of 1124 participants, 98 (8.7%) report having a healthcare provider make a diagnosis of long covid. By arm, 6.9% (39/564) of metformin participants report having a diagnosis for long covid as compared with 10.5% (59/560) of matched placebo controls. The absolute reduction attributable to metformin was 3.6% (95%CI, 0.3% to 7.0%;P=0.031) with a relative risk reduction of 34% (95%CI, 3% to 55%). The metformin cost per long covid case averted was $28 (95%CI, $15 to $306). 10-month follow-up data will be available at the time of presentation as well as an analysis of baseline factors associated with the development of Long-Covid, independent of treatment allocation in the trial. DISCUSSION/SIGNIFICANCE: Metformin reduced the incidence of clinician-diagnosed long covid by 34% in a double-blind randomized placebo-controlled trial, and previous research published in-vitro activity by metformin against SARS-CoV-2 and other RNA viruses. Further investigation of metformin as early treatment for SARS-CoV-2 is warranted.

Effect of Fluvoxamine on Interleukin-6 Levels in COVID-19 Patients Hospitalized in ICU: A Randomized Clinical Trial

Background: Reviewing the laboratory studies, we observe some drugs with other specified applications, which cause serious inhibitory immune responses in the body. Selective Serotonin Reuptake Inhibitors (SSRIs) are among these drugs. Therefore, the current research aimed to evaluate the effectiveness of one of the SSRI drugs called fluvoxamine on the cytokine levels in COVID-19 patients. Material(s) and Method(s): The current research included 80 patients with COVID-19 hospitalized in ICU in Massih Daneshvari Hospital. They were entered into the research by an accessible method of sampling and then divided into two groups randomly. One of the groups underwent the treatment with fluvoxamine as the experimental group and the other group did not receive fluvoxamine as the control group. Interleukin-6 (IL-6) and CRP levels were measured before the onset of fluvoxamine consumption and when discharging from the hospital in all members of the sample group. Result(s): The current study showed that IL-6 levels increased, while CRP levels decreased in the experimental group significantly (P-value<= 0.01). After consuming fluvoxamine, IL-6 and CRP levels were higher and lower in the females compared to the males, respectively. Conclusion(s): Considering the effectiveness of fluvoxamine on IL-6 and CRP in COVID-19 patients, it may ultimately come true to use this drug to improve both psychological and physical conditions simultaneously and leave the COVID-19 pandemic behind with less pathology.Copyright © 2022 NRITLD, National Research Institute of Tuberculosis and Lung Disease, Iran.

Treatment with fluvoxamine in nonhospitalized coronavirus disease 2019 patients

Context: Fluvoxamine may have a potential immune-regulatory action and a therapeutic role in severe acute respiratory syndrome-coronavirus (SARS-CoV-2) infection that may prevent progression and/or hospitalization. Aim(s): Trial that compared fluvoxamine versus placebo in nonhospitalized adults with confirmed SARS-CoV-2 infection (mild and moderate coronavirus disease 2019 cases). Settings and design: This is a double-blinded, randomized clinical trial. Patients and Methods: The study enrolled 162 cases with positive PCR assay for SARS-CoV-2 infection and who were symptomatic within 7 days of the first dose of study medication. Statistical analysis: The demographic, clinical, and laboratory data gathered together will be tabulated and statistically analyzed. The statistical analysis of data was carried out using Excel and the SPSS programs statistical package for AQ8 Social Sciences, version 17. Quantitative data were described as median (minimum-maximum). An analysis of the data was carried out to test statistically significant differences between groups. Quantitative data were presented as mean+/-SD and the Student's t test was used to compare between two groups. Result(s): In all, 162 patients completed the study;72 patients were of mild severity;90 patients were moderate cases and each group was randomized to receive fluvoxamine or placebo besides standard care. In the mild group, no significant difference was recorded while slight significance exists in the moderate severity group. Conclusion(s): Fluvoxamine may have an added value besides the current standard care in reducing the need for hospitalization in outpatient cases, especially pneumonic ones;however, more larger studies are needed. Copyright © 2023 The Egyptian Journal of Chest Diseases and Tuberculosis.

Trial Sequential Analysis and Updated Meta-Analysis of Fluvoxamine on Clinical Deterioration in Adult Patients with Symptomatic COVID-19 Infection.

Preliminary meta-analyses suggested that fluvoxamine was effective in treating COVID-19 infection. However, the reliability of this evidence has not yet been examined. MEDLINE, CENTRAL, EMBASE, PsycINFO, and ClinicalTrials.gov were searched to identify any randomized controlled trials (RCTs) from the inception of the databases to 5 February 2023. We used trial sequential analysis (TSA) to examine the reliability of the current existing evidence on the benefits of fluvoxamine on COVID-19 infection. The primary outcome was clinical deterioration, as defined in the original study (reported as odds ratio (OR), with 95% confidence intervals), and the secondary outcome was hospitalization. In the TSA, we used the relative risk reduction thresholds of 10, 20, and 30%. The updated meta-analysis of the five RCTs showed that fluvoxamine was not associated with lower odds of clinical deterioration when compared with a placebo (OR: 0.81; 0.59-1.11). The effect of fluvoxamine lay within the futility boundary (i.e., lack of effect) when using a 30% relative risk reduction threshold. The effect estimates lay between the superiority and futility boundary using the 10% and 20% threshold, and the required size of information was not reached for these two thresholds. The effect of fluvoxamine on the odds of hospitalization was not statistically significant (0.76; 0.56-1.03). In conclusion, there is no reliable evidence that fluvoxamine, when compared to a placebo, reduces the relative risk of clinical deterioration among adult patients with COVID-19 infection by 30%, and a relative risk reduction of 20% or 10% is still uncertain. The role of fluvoxamine as a COVID-19 treatment cannot be justified.

Overview of the potential use of fluvoxamine for COVID-19 and long COVID.

Coronavirus disease 2019 (COVID-19) has presented a serious worldwide threat to public health since its emergence in late 2019. From a safety point of view, drug repurposing has received particular attention. Several clinical studies have demonstrated that the use of fluvoxamine, a selective serotonin reuptake inhibitor with potent sigma-1 receptor agonism, in the early-stage of infection might be associated with the prevention of clinical deterioration in individuals with SARS-CoV-2 infection, although several reports have shown that a low dose of fluvoxamine may be ineffective. There is increasing evidence that SARS-CoV-2 can cross the blood-brain barrier, resulting in a number of psychiatric and neurologic symptoms in COVID-19 survivors. Importantly, about half of COVID-19 survivors experience a variety of long-term sequelae, including psychiatric and neurologic symptoms, known as long COVID. In this priority review, the author presents an overview of the potential use of fluvoxamine in the treatment of COVID-19 and long COVID.

Effect of fluvoxamine on preventing neuropsychiatric symptoms of post COVID syndrome in mild to moderate patients, a randomized placebo-controlled double-blind clinical trial.

BACKGROUND: Shortly after the Coronavirus disease 2019 (COVID-19) pandemic, a considerable number of recovered patients reported persisting symptoms, especially neuropsychological manifestations, which were later named post-COVID syndrome (PCS). Immune dysregulation was suggested as one of the main mechanisms for PCS. Fluvoxamine, a selective serotonin reuptake inhibitor (SSRI) that is mostly used to treat depression, anxiety disorders, and obsessive-compulsive disorder, has been suggested as an anti-COVID drug due to its anti-inflammatory effects, mainly through the sigma-1 receptor. Therefore, we aimed to evaluate fluvoxamine's effect on PCS neuropsychiatric symptoms. METHOD: In this double-blind randomized clinical trial, we included confirmed mild to moderate COVID-19 outpatients using polymerase chain reaction (PCR) by an infectious disease specialist. The presence of severe COVID-19 symptoms was evaluated by the infectious disease specialist and included dyspnea, SpO2 < 94% on room air, PaO2/FiO2 < 300 mm Hg, a respiratory rate > 30 breaths/min, and lung infiltrates > 50%. Then we performed permuted block randomization and assigned patients 1:1 into two groups to either receive fluvoxamine 100 mg tablet or a placebo daily for 10 days. Eligible patients were evaluated after 12 weeks for the presence of fatigue, as the primary, and other PCS symptoms as secondary outcomes. RESULTS: We screened a total of 486 patients from March to June 2022. After 12 weeks, 42 patients receiving fluvoxamine and 43 patients receiving Placebo were evaluated for PCS. Patients had a mean age of 38.5 ± 14.1 and 48% of them were women. Fatigue was significantly lower in the fluvoxamine group (p-value 0.026). No significant differences were observed in other symptoms. CONCLUSION: We concluded that taking fluvoxamine during active COVID-19 can reduce the chance of fatigue but the advantage of fluvoxamine was not observed for other symptoms. Further studies are necessary to confirm these preliminary results.

Efficacy and Safety of Fluvoxamine as Outpatient Treatment for Patients With Covid-19: A Systematic Review and Meta-analysis of Clinical Trials.

BACKGROUND: Fluvoxamine may be beneficial for the management of coronavirus disease 2019 (Covid-19) because of its effect on the sigma-1 receptor. Available evidence from randomized clinical trials (RCTs) has shown conflicting results. OBJECTIVE: This study sought to analyze the efficacy and safety of fluvoxamine as an outpatient treatment for Covid-19. METHODS: Using specific keywords, we comprehensively go through the potential articles on PubMed, Scopus, Europe PMC, and ClinicalTrials.gov sources until February 1, 2023. We collected all published clinical trials on fluvoxamine and Covid-19. We were using Review Manager 5.4 to conduct statistical analysis. RESULTS: We include a total of 6 trials. Our pooled analysis revealed that fluvoxamine did not offer any significant benefit when compared with placebo in reducing the risk of clinical deterioration (risk ratio [RR] = 0.83; 95% CI: 0.65-1.06, P = 0.14, I2 = 29%), and hospitalization (RR = 0.80; 95% CI: 0.62-1.04, P = 0.09, I2 = 0%) of Covid-19 outpatients. The serious adverse events did not differ significantly between the 2 groups. CONCLUSIONS AND RELEVANCE: This study indicates that although safe, fluvoxamine was not effective for outpatient treatment of Covid-19. Until more evidence can be obtained from larger RCTs, our study did not encourage the use of fluvoxamine as routine management for patients with Covid-19.

Outpatients prescribed with fluvoxamine around the time of COVID-19 diagnosis are not at a reduced risk of subsequent hospitalization and death compared to their non-prescribed peers: population-based matched cohort study.

PURPOSE: To assess the effect of exposure to fluvoxamine around the COVID-19 diagnosis on subsequent hospitalizations and mortality in COVID-19 outpatients in a real-life setting. METHODS: Using nationwide administrative data, we identified adult COVID-19 outpatients diagnosed up to August 15, 2021 and conducted two cohort studies. Study 1 included subjects prescribed fluvoxamine around the index COVID-19 diagnosis (Cohort A), their peers suffering similar psychiatric difficulties but not prescribed fluvoxamine (Cohort B) and those free of psychiatric difficulties/treatments (Cohort C). Study 2 included subjects prescribed fluvoxamine (Cohort Fluvoxamine) and their peers prescribed paroxetine (Cohort Paroxetine). Cohorts were mutually exactly matched and incidence of COVID-19-related hospitalization, 30-day all-cause hospitalization and of COVID-19-related mortality was estimated. RESULTS: Of the 416,030 first-episode outpatients, Study 1 included 1016 Cohort A, 95,984 Cohort B and 275,804 Cohort C patients. Matched Cohort A (n = 749) vs. Cohort B (n = 31,336) relative risks (95%CI/CrI), frequentist and Bayes with skeptical, otpimistic and pesimistic priors, were COVID-related hospitalization 1.37 (0.56-3.33), 1.15 (0.55-2.11), 1.03 (0.56.1.96) and 1.43 (0.63-2.94), respectively; 30-day all-cause hospitalization 1.88 (0.76-4.67), 1.76 (1.39-2.25), 1.76 (1.39-2.24) and 1.86 (1.43-2.38), respectively; COVID-19-related mortality 0.73 (0.35-1.55), 0.93 (0.53-1.76), 0.79 (0.40-1.54) and 0.88 (0.37-2.11), respectively. Matched Cohort A vs. C (866 vs. 222,792) comparison yielded similar estimates, as did the matched Cohort Fluvoxamine vs. Paroxetine comparison in Study 2 (344 of 994 matched to 535 of 1796 patients). CONSLUSION: Outpatients prescribed fluvoxamine around the time of COVID-19 diagnosis were not at a reduced risk of hospitalizations and mortality compared to their non-prescribed peers.

Correction of Psychoemotional Disorders and Short-Term Prognosis in Patients with COVID-19.

This review discusses the importance of the main psychoemotional risk factors for the development of chronic noncommunicable diseases. Current data on the prevalence of anxiety and depressive disorders in patients with cardiovascular disease (CVD) are presented. Data on the relationship between the development of psychoemotional disorders and CVD are summarized and the prospects for managing such patients within the framework of interdisciplinary cooperation are discussed. The main pathogenetic mechanisms for the development of complications, including CNS damage in COVID-19, are considered. The significance of the selection of pathogenetic therapy for patients with comorbid somatic and mental diseases in the context of the COVID-19 pandemic is discussed. Results from multicenter placebo-controlled studies of the use of fluvoxamine in patients with COVID-19 of varying severity are addressed.

An Overview of Fluvoxamine and its Use in SARS-CoV-2 Treatment.

Fluvoxamine (FLV) is a well-tolerated, widely accessible antidepressant of the selective serotonin reuptake inhibitor (SSRI) category. It was formerly used to reduce anxiety, obsessive-compulsive disorder, panic attacks, and depression. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an enclosed ribonucleic acid (RNA) virus with a positive-sense RNA genome that belongs to the Coronaviridae family. Infection with SARS-CoV-2 causes clinical deterioration, increased hospitalization, morbidity, and death. As a result, the purpose of this research was to review FLV and its use in the treatment of SARS-CoV-2. FLV is a potent sigma-1 receptor (S1R) agonist that modulates inflammation by reducing mast cell downregulation, cytokine production, platelet aggregation, interfering with endolysosomal viral transport, and delaying clinical deterioration. FLV treatment reduced the requirement for hospitalization in high-risk outpatients with early identified coronavirus disease 2019 (COVID-19), defined by detention in a COVID-19 emergency department or transfer to a tertiary hospital. In addition, FLV may reduce mortality and risk of hospital admission or death in patients with SARS-CoV-2. The most common adverse effect is nausea; other gastrointestinal symptoms, neurologic consequences, and suicidal thoughts may also occur. There is no evidence that FLV can treat children with SARS-CoV-2. Although FLV is not expected to increase the frequency of congenital abnormalities during pregnancy, this risk must be balanced with the potential benefit. More research is required to determine the effectiveness, dose, and mechanisms of action of FLV; however, FLV appears to offer significant promise as a safe and widely accessible drug that can be repurposed to reduce substantial morbidity and mortality due to SARS-CoV-2.

Antidepressants for COVID-19: A systematic review.

OBJECTIVE: To systematically examine the efficacy and safety of antidepressants for the treatment of coronavirus disease 2019 (COVID-19). METHODS: A systematic search was performed independently by two researchers based on Chinese Journal Net, WanFang, PsycINFO, Cochrane Library, PubMed, and EMBASE. RESULTS: Seven studies (n = 92,947) including three retrospective studies (n = 91,083), two randomized clinical trials (RCTs, n = 1649), two prospective cohort study (n = 215) involving (n = 92,947) patients with COVID-19 were examined. For RCTs, fluvoxamine outperformed placebo in reducing clinical deterioration and hospitalisation for COVID-19 patients. For retrospective studies, antidepressants (2 studies) and fluoxetine (1 study) possibly reduced the risk of mortality in patients with COVID-19. Results from two remaining studies supported the superiority of fluvoxamine in reducing risk of mortality in COVID-19 patients. The two RCTs that examined the safety of fluvoxamine for COVID-19 patients found inconsistent results but no significant group differences in the dropout rate. CONCLUSION: This systematic review found emerging evidence for fluvoxamine in reducing the risk of mortality and hospitalisation in COVID-19 patients, but inconsistent evidence for the safety of fluvoxamine in COVID-19 patients. More studies are needed to determine the efficacy and safety of antidepressants for the treatment of COVID-19.

Pharmacological treatment of COVID-19: an opinion paper.

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.

Potential Role of the Antidepressants Fluoxetine and Fluvoxamine in the Treatment of COVID-19.

Mapping non-canonical cellular pathways affected by approved medications can accelerate drug repurposing efforts, which are crucial in situations with a global impact such as the COVID-19 pandemic. Fluoxetine and fluvoxamine are well-established and widely-used antidepressive agents that act as serotonin reuptake inhibitors (SSRI-s). Interestingly, these drugs have been reported earlier to act as lysosomotropic agents, inhibitors of acid sphingomyelinase in the lysosomes, and as ligands of sigma-1 receptors, mechanisms that might be used to fight severe outcomes of COVID-19. In certain cases, these drugs were administered for selected COVID-19 patients because of their antidepressive effects, while in other cases, clinical studies were performed to assess the effect of these drugs on treating COVID-19 patients. Clinical studies produced promising data that encourage the further investigation of fluoxetine and fluvoxamine regarding their use in COVID-19. In this review, we summarize experimental data and the results of the performed clinical studies. We also provide an overview of previous knowledge on the tissue distribution of these drugs and by integrating this information with the published experimental results, we highlight the real opportunity of using these drugs in our fight against COVID-19.

Efficacy and safety of selective serotonin reuptake inhibitors in COVID-19 management: a systematic review and meta-analysis.

BACKGROUND: The efficacy of selective serotonin reuptake inhibitors (SSRIs) in the treatment of acute COVID-19 is still under investigation, with conflicting results reported from randomized controlled trials (RCTs). Different dosing regimens may have contributed to the contradictory findings. OBJECTIVES: To evaluate the efficacy and safety of SSRIs and the effect of different dosing regimens on the treatment of acute COVID-19. DATA SOURCES: Seven databases were searched from January 2020 to December 2022. Trial registries, previous reviews, and preprint servers were hand-searched. STUDY ELIGIBILITY CRITERIA: RCTs and observational studies with no language restrictions. PARTICIPANTS: COVID-19 inpatients/outpatients. INTERVENTIONS: SSRIs prescribed after diagnosis were compared against a placebo or standard of care. ASSESSMENT OF RISK OF BIAS: Risk of bias was rated using the revised Cochrane Risk of Bias Tool for Randomized Trials version 2.0 and Risk of Bias in Non-Randomized Studies of Interventions. METHODS OF DATA SYNTHESIS: Outcomes were mortality, hospitalization, composite of hospitalization/emergency room visits, hypoxemia, requirement for supplemental oxygen, ventilator support, and serious adverse events. RCT data were pooled in random-effects meta-analyses. Observational findings were narratively described. Subgroup analyses were performed on the basis of SSRI dose, and sensitivity analyses were performed excluding studies with a high risk of bias. The Grading of Recommendations, Assessment, Development and Evaluations framework was used to assess the quality of evidence. RESULTS: Six RCTs (N = 4197) and five observational studies (N = 1156) were included. Meta-analyses associated fluvoxamine with reduced mortality (risk ratio, 0.72; 95% CI, 0.63-0.82) and hospitalization (risk ratio, 0.79; 95% CI, 0.64-0.99) on the basis of moderate quality of evidence. Medium-dose fluvoxamine (100 mg twice a day) was associated with reduced mortality, hospitalization, and composite of hospitalization/emergency room visits, but low-dose fluvoxamine (50 mg twice a day) was not. Fluvoxamine was not associated with increased serious adverse events. Observational studies support the use of fluvoxamine and highlight fluoxetine as a possible alternative to SSRIs for the treatment of COVID-19. DISCUSSION: Fluvoxamine remains a candidate pharmacotherapy for treating COVID-19 in outpatients. Medium-dose fluvoxamine may be preferable over low-dose fluvoxamine.