Efficacy of combination therapy of fluvoxamine and favipiravir vs favipiravir monotherapy to prevent severe COVID-19 among mild to moderate COVID-19 patients: Open-label randomized controlled trial (EFFaCo study)

Objectives: Fluvoxamine (FVX) is an antidepressant proposed to its immunomodulatory effects in preventing deterioration in mild and moderate COVID-19.Methods: An open-label, 1:1 randomized controlled trial was assigned either combination therapy 50 mg twice daily of FVX for 10 days and favipiravir (FPV) or FPV alone to assess the efficacy in preventing disease progression in mild to moderate COVID-19 on the 5 th day. Results: In total, 134 patients with mild COVID-19 received FPV and 132 received FVX/FPV, 31 patients with moderate COVID-19 received FPV/dexamethasone (FPV/Dex), and 30 received FVX/FPV/Dex. The intention-to-treat (ITT) analysis showed no difference of no clinical deterioration on the 5 th day in both mild COVID-19 (100% in FPV vs 97% in FVX/FPV) and moderate COVID-19 (83.9% in FPV/Dex vs 86.7% in FVX/FPV/Dex). However, there was a low rate of oxygen supplemental, hospitalization, or intensive care in both groups and zero death in all groups. No significant difference in oxygen supplemental, hospitalization, radiological, virological, or biochemical outcomes, and the immunomodulatory effect was observed between the group.Conclusion: The combined fluvoxamine treatment did not add benefit in preventing deterioration in patients with mild to moderate COVID-19 without the immunomodulatory effect observed, although it demonstrated low hospitalization rates, oxygen supplemental, intensive care needed, and zero mortality.Trial Registration: Thai clinical trials registry (TCTR) no. 20210615002.& COPY; 2023 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )