Effect of Higher-Dose Fluvoxamine vs Placebo on Time to Sustained Recovery in Outpatients with Mild to Moderate COVID-19: A Randomized Clinical Trial

Assessing the effect of selective serotonin reuptake inhibitors in the prevention of post-acute sequelae of COVID-19

Background

Post-acute sequelae of COVID-19 (PASC) produce significant morbidity, prompting evaluation of interventions that might lower risk. Selective serotonin reuptake inhibitors (SSRIs) potentially could modulate risk of PASC via their central, hypothesized immunomodulatory, and/or antiplatelet properties although clinical trial data are lacking.

Materials and Methods

This retrospective study was conducted leveraging real-world clinical data within the National COVID Cohort Collaborative (N3C) to evaluate whether SSRIs with agonist activity at the sigma-1 receptor (S1R) lower the risk of PASC, since agonism at this receptor may serve as a mechanism by which SSRIs attenuate an inflammatory response. Additionally, determine whether the potential benefit could be traced to S1R agonism. Presumed PASC was defined based on a computable PASC phenotype trained on the U09.9 ICD-10 diagnosis code.

Results

Of the 17,908 patients identified, 1521 were exposed at baseline to a S1R agonist SSRI, 1803 to a non-S1R agonist SSRI, and 14,584 to neither. Using inverse probability weighting and Poisson regression, relative risk (RR) of PASC was assessed.A 29% reduction in the RR of PASC (0.704 [95% CI, 0.58-0.85]; P = 4 ×10-4) was seen among patients who received an S1R agonist SSRI compared to SSRI unexposed patients and a 21% reduction in the RR of PASC was seen among those receiving an SSRI without S1R agonist activity (0.79 [95% CI, 0.67 - 0.93]; P = 0.005).Thus, SSRIs with and without reported agonist activity at the S1R were associated with a significant decrease in the risk of PASC.

[The Impact of Antidepressants on COVID-19 and Post-Acute COVID-19 Syndrome: A Scoping-Review Update]

Introduction Preclinically, fluvoxamine and other antidepressants (AD) exerted antiviral and anti-inflammatory properties also against SARS-COV-2. Therfore, It makes sense to test the clinical effect of AD against COVID-19 and Long COVID.

METHODS

On May 20, 2024, this systematic scoping review in PUBMED identified 1016 articles related to AD and COVID-19, Long COVID and SARS-COV-2. These included 10 retrospective "large scale" studies (> 20000 chart reviews), 8 prospective clinical trials (plus 4 regarding Long COVID), 11 placebo-controlled randomized (RCT) (plus 2 regarding Long COVID) and 15 meta-analyses.

RESULTS

COVID-19: Retrospective studies with cohorts taking AD primarily for psychiatric comorbidities or chronic pain conditions directly prior to SARS-COV-2 infection described that this substance class (most studied: Selective Serotonin Re-Uptake Inhibitors (SSRI) and Selective Serotonin Noradrenaline Re-Uptake Inhibitors (SSNRI)) were associated with (i) significantly fewer SARS-COV-2 infections and (ii) a milder course of COVID-19 ("COVID-19 protection"). Ten of the 11 RCTs found regarding COVID-19 tested fluvoxamine, as this old AD appeared suitable as a prophylactic agent against severe COVID-19, taking into account its in vitro potency against the progression of intracellular sepsis cascades. Therefore, most (12 out of 15) meta-analyses also referred to fluvoxamine. They found (iii) a significant (40-70% reduction) in mortality, intubation and hospitalization rates when fluvoxamine was used as an add-on to standard therapy for mild to moderate COVID-19. When this AD was used in the early stages of the disease, it was more successful than when it was given later in advanced, severe COVID-19 (e.g. severe pneumonia, final sepsis stages). A dose dependency was observed: 2x50 mg fluvoxamine over 15 days was less effective than 2x100 or even 3x100 mg with an adverse event profile still at the placebo level. Direct comparisons with drugs approved for COVID-19 do not yet exist. A first indirect meta-analytical comparison showed an advantage of paxlovid or molnupiravir versus fluvoxamine against the development of severe COVID-19: risk reduction of 95% (I2 = N/A, but only one study) or 78% (I2=0) versus 5+-5% (I2=48). However, an add-on of fluvoxamine was still significantly more efficacious than symptom-oriented standard therapy alone. Long COVID: A common Long COVID phenotype with dominant anxiety and depression symptoms, which responds to AD, relaxation therapy and/or psychotherapy, has now been identified. Casuistics report positive effects of AD on fatigue, cognitive and autonomic dysfunctions. A first large prospective open-label RCT has just shown significantly more favourable courses, less viral load and less pro-inflammatory cytokines in the treatment of mild to moderate COVID-19 with fluvoxamine versus standard treatment, also with regard to the subsequent development of neuropsychiatric and pulmonary Long COVID or fatigue.

CONCLUSION

Overall, there is promising evidence of a preventive effect of AD (especially fluvoxamine) against progression to severe COVID-19 and against the development of Long COVID. It is likely, that the entire AD substance class could be effective here. This assumption is based on the results of retrospective large scale studies, but awaits verification by better controlled studies. The potential effectiveness/efficacy (currently low and moderate confidence of the evidence for the entire substance class and specifically fluvoxamine, respectively) of fluvoxamine as an add-on against COVID-19 and possibly also directly against Long COVID could stimulate similar projects in other infectious diseases that also have the potential to pose a lasting threat to the health of those affected. We consider the evidence to date to be sufficient to be able to emphasize a possible positive effect of these substances in the psychoeducation of patients with COVID-19 or Long COVID who are already receiving AD for other conditions - especially also against the symptoms associated with the viral disease or its consequences. In regions where neither vaccines nor antiviral agents currently approved for the prevention or treatment of COVID-19 are available, AD and in particular fluvoxamine would be a cost-effective alternative to protect against a severe course, even if this AD appears to have a smaller effect against COVID-19 than the currently approved antiviral agents, but with presumably better tolerability. A direct comparative clinical trial with approved antiviral agents is still pending and should be positive to further open the door for a guideline-based recommendation of fluvoxamine (or perhaps even AD) for COVID-19 or its aftermath.

Evaluating fluvoxamine for the outpatient treatment of COVID-19: A systematic review and meta-analysis

This systematic review and meta-analysis of randomised controlled trials (RCTs) aimed to evaluate the efficacy, safety, and tolerability of fluvoxamine for the outpatient management of COVID-19. We conducted this review in accordance with the PRISMA 2020 guidelines. Literature searches were conducted in MEDLINE, EMBASE, International Pharmaceutical Abstracts, CINAHL, Web of Science, and CENTRAL up to 14 September 2023. Outcomes included incidence of hospitalisation, healthcare utilization (emergency room visits and/or hospitalisation), mortality, supplemental oxygen and mechanical ventilation requirements, serious adverse events (SAEs) and non-adherence. Fluvoxamine 100 mg twice a day was associated with reductions in the risk of hospitalisation (risk ratio [RR] 0.75, 95% confidence interval [CI] 0.58-0.97; I 2  = 0%) and reductions in the risk of healthcare utilization (RR 0.68, 95% CI 0.53-0.86; I 2  = 0%). While no increased SAEs were observed, fluvoxamine 100 mg twice a day was associated with higher treatment non-adherence compared to placebo (RR 1.61, 95% CI 1.22-2.14; I 2  = 53%). In subgroup analyses, fluvoxamine reduced healthcare utilization in outpatients with BMI ≥30 kg/m2 , but not in those with lower BMIs. While fluvoxamine offers potential benefits in reducing healthcare utilization, its efficacy may be most pronounced in high-risk patient populations. The observed non-adherence rates highlight the need for better patient education and counselling. Future investigations should reassess trial endpoints to include outcomes relating to post-COVID sequelaes. Registration: This review was prospectively registered on PROSPERO (CRD42023463829).