Effectiveness and Safety of Favipiravir Compared to Hydroxychloroquine for Management of Covid-19: A Retrospective Study.

Background: Coronavirus disease (COVID-19) is an infectious disease due to SARS-COV-2. Patients with risk factors are vulnerable to severe morbidity and mortality. Favipiravir (FPV) and hydroxychloroquine (HCQ) are considered possible COVID-19 treatments.

Objective: To investigate the effectiveness and safety of FPV compared to HCQ in patients with COVID-19 as the standard of care approved by the national protocol there.

Methods: This is a retrospective cohort study on patients with COVID-19 who were administered either FPV or HCQ at King Faisal Medical Complex, Taif, Saudi Arabia, from June 2020 to August 2020.

Results: In total, 508 patients were included in the analysis. Patients were categorized into three groups by medication. Patients enrolled in this study were 244 (55.8%) on FPV, 193 (44.2%) on HCQ and 71 (13.81%) on neither medication. Patients who received FPV had higher age and greater comorbidity. Most of the patients were discharged on day 14 (n = 303, 59.6%), 26 (36.6%) in neither med, 154 (63.1%) in FPV and 123 (63.7%) in HCQ groups with significant difference between groups ( < 0.0001). Mortality rate was 8.2% (n = 20) in FPV and 7.3% (n = 14) in HCQ groups with significant difference between groups (P = 0.048). Regarding drug safety, 19.7% of patients treated with FPV vs 7.8% HCQ have adverse effects with significant difference between groups ( < 0.0001). Most of the side effects were increase ALT and AST. Meanwhile, prolonged Q-T interval was reported only in the HCQ group (2.6%). From Cox regression modeling, only mechanical ventilation due to Covid 19 was predictive for mortality (HR: 16.598, 95% CI: 7.095-38.828, P < 0.0001). Meanwhile, there was no significant difference in the prediction of discharge of FPV (vs HCQ) (HR: 0.933, 95% CI: 0.729-1.195, = 0.5843), predictors of mortality were HCQ (vs FPV) (HR: 2.3, 95% CI: 0.994-5.487, = 0.0518). Kaplan-Meier survival curves showed improved survival time and discharged time among patients in the HCQ versus FPV group with an insignificant difference between them ( = 0.85, = 0.06, respectively).

Conclusion: The present study concluded that FPV and HCQ showed comparable efficacy in decrease mortality and oxygen requirements. FPV likely has a more favorable safety profile regarding cardiac toxicity. A randomized clinical trial with large patient numbers is recommended to confirm the effectiveness of these drugs in COVID-19 patients.