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.