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Favipiravir for COVID-19
74 studies with >30,000 patients
Significantly lower risk for recovery and viral clearance.
Potential risks include kidney injury, liver injury, cardiovascular toxicity, pulmonary toxicity, mutagenicity, carcinogenicity, teratogenicity, embryotoxicity, and the creation of dangerous variants.
COVID-19 Favipiravir studies · October 2026
Potential risks include kidney injury1-3, liver injury2-5, cardiovascular toxicity5,6, pulmonary toxicity6,7, and mutagenicity, carcinogenicity, teratogenicity, embryotoxicity, and the creation of dangerous variants8-14. Favipiravir may impair clotting15. Variants may be less susceptible to favipiravir16. Favipiravir was adopted in 21 countries. Recent:
Wawman
Rowland.
Covid Analysis Favipiravir for COVID-19: real-time meta-analysis of 74 studies (Version 89)
Significantly lower risk is seen for recovery and viral clearance. 32 studies from 32 independent teams in 16 countries show significant benefit. Meta-analysis using the most serious outcome reported shows 11% [3‑18%] lower ris..
Mar 26
 Wawman et al., ERJ Open Research, doi:10.1183/23120541.01560-2025 The Relationship Between Plasma Favipiravir Concentrations and Clinical Outcomes in COVID-19
Post hoc pharmacokinetic analysis of 140 hospitalized COVID-19 patients from the PIONEER RCT, showing no statistically significant improvement in clinical outcomes among favipiravir-treated patients who achieved target plasma concentratio..
Mar 18
 Rowland et al., Clinical Pharmacology & Therapeutics, doi:10.1002/cpt.70261 Optimal Dose and Safety of Intravenous Favipiravir in Hospitalized Patients With COVID-19: A Dose-Escalating, Randomized Controlled Phase Ib Study
Phase Ib dose-escalating RCT of 24 hospitalized COVID-19 patients showing safety and tolerability of intravenous (IV) favipiravir at doses up to 2,400 mg twice daily.
Jan 14
 Siripongboonsitti et al., Journal of Infection and Public Health, doi:10.1016/j.jiph.2026.103150 Post-Exposure Prophylaxis with Favipiravir among Household Close Contacts to Confirmed COVID-19 Cases: A Cluster-Randomized Trial (PEPfavi)
50% fewer symptomatic cases (p=0.37) and 36% fewer cases (p=0.46). RCT 168 household close contacts showing no significant difference in SARS-CoV-2 infection with favipiravir post-exposure prophylaxis. The primary endpoint of laboratory-confirmed infection by day 14 occurred in 7.3% of the favipiravir gr..
Jan 14
 Ozhan et al., Scientific Reports, doi:10.1038/s41598-025-31048-4 Evaluation of the cardiopulmonary effects of repurposed COVID-19 therapeutics in healthy rats
Animal study analyzing potential cardiopulmonary harm with molnupiravir (MOL), favipiravir (FAVI), hydroxychloroquine (HCQL), and dexamethasone (DEX) in healthy Wistar albino rats. In summary: Data suggests molnupiravir may have the highe..
Jan 11
 Siby et al., Open Forum Infectious Diseases, doi:10.1093/ofid/ofaf695.1825 Temporal Trends in Serious Adverse Events Associated with Oral Antivirals During the COVID-19 Pandemic: Insights from the FAERS Database (2020–2023)
Retrospective 11,547 serious adverse event reports from the FDA database (2020-2023) showing significant safety signals with oral COVID-19 antivirals. Paxlovid showed the strongest signals for drug-drug interactions (ROR: 4.83) and liver ..
Jul 31
2025
 Sirijatuphat et al., Phytomedicine Plus, doi:10.1016/j.phyplu.2025.100858 Andrographis paniculata or Favipiravir in Mild COVID-19: A Randomized Control Trial
RCT 184 mild COVID-19 patients in Thailand showing no difference in pneumonia incidence or viral clearance between Andrographis paniculata and favipiravir.
Jun 26
2025
 Shen et al., Pharmaceutics, doi:10.3390/pharmaceutics17070832 Carboxylesterase Factors Influencing the Therapeutic Activity of Common Antiviral Medications Used for SARS-CoV-2 Infection
Review of how carboxylesterase (CES) enzymes influence the activity of certain COVID-19 antivirals, focusing on remdesivir, molnupiravir, nirmatrelvir, and favipiravir. Authors highlight that remdesivir requires activation by CES1, while ..
Jun 24
2025
 Tate et al., Antimicrobial Agents and Chemotherapy, doi:10.1128/aac.00054-25 Clinical effectiveness, safety, and viral mutagenicity of oral favipiravir for COVID-19: results from a community-based, open-label, randomized Phase III trial
34% lower hospitalization (p=0.68), 21% improved 7-point scale results (p=0.61), 3% improved recovery (p=0.82), and 12% improved viral clearance (p=0.68). RCT 302 outpatients with mild COVID-19 showing no significant difference in outcomes with favipiravir treatment. The study population was relatively young and had few comorbidities, resulting in a low incidence of severe disease. Favipira..
Jun 23
2025
 Noomcharoen et al., Journal of the Medical Association of Thailand, doi:10.35755/jmedassocthai.2025.6.431-439-01780 Favipiravir Exposure in the Second and Third Trimesters of Pregnancy with COVID-19: Risk of Adverse Perinatal Outcomes: A Retrospective Cohort Study
Retrospective 214 pregnant women with COVID-19 showing increased risk of small for gestational age (SGA) infants with favipiravir exposure during the second and third trimesters.
Jun 9
2025
 Rowland et al., medRxiv, doi:10.1101/2025.06.09.25329141 Optimal dose and safety of intravenous favipiravir in hospitalised patients with SARS-CoV-2 infection: a Phase Ib, open-label, dose-escalating, randomised controlled study
RCT 24 hospitalized COVID-19 patients (16 treatment, 8 standard of care) evaluating safety and pharmacokinetics of intravenous favipiravir at escalating doses. The study found that IV favipiravir was safe and well-tolerated up to 2400mg t..
Jun 4
2025
 Lumkul et al., PLOS One, doi:10.1371/journal.pone.0324903 In-hospital mortality outcomes of favipiravir in patients with moderate to severe COVID-19 infection: An emulated target trial using real-world data from the largest field hospital in Thailand
4% improved survival (p=0.004). Retrospective 3,193 moderate to severe COVID-19 patients in Thailand showing modest survival benefits with favipiravir. This emulated target trial found that favipiravir alone increased restricted mean survival time by 1.32 days (p=0.042)..
Apr 29
2025
 Ülger et al., Food and Chemical Toxicology, doi:10.1016/j.fct.2025.115472 Experimental evaluation of favipiravir (T-705)-induced liver and kidney toxicity in rats
Rat study showing dose-dependent liver and kidney toxicity with favipiravir. Authors note that lesions worsened at medium and high-dose levels and propose that co-administration of antioxidant or anti-inflammatory treatments might mitigat..
Apr 6
2025
 Cenikli et al., Talanta, doi:10.1016/j.talanta.2025.128084 Does Favipiravir interact with DNA? Design of electrochemical DNA nanobiosensor to investigate the interaction between DNA and Favipiravir used in the treatment of COVID-19
Favipiravir exhibits a direct interaction with DNA, as detected by a novel electrochemical nanobiosensor. Authors observed a decrease in guanine oxidation signals that suggests favipiravir may bind to or alter DNA structure, raising conce..
Feb 12
2025
 Saha et al., Viruses, doi:10.3390/v17020252 Inhaled Dry Powder of Antiviral Agents: A Promising Approach to Treating Respiratory Viral Pathogens
Review of inhaled dry powder antiviral formulations for treating respiratory viral infections, focusing on COVID-19. Authors explain that traditional antiviral tablets face limitations including systemic side effects and delayed onset of ..
Jan 11
2025
 Ülger et al., Food and Chemical Toxicology, doi:10.1016/j.fct.2025.115235 Evaluation of the effects of favipiravir (T-705) on the lung tissue of healty rats: An experimental study
Animal study showing dose-dependent lung inflammation and fibrosis with favipiravir.
Jan 1
2025
 Abdulaziz et al., Mansoura Medical Journal, doi:10.58775/2735-3990.1433 Clinical Features and Prognosis of Acute Kidney Injury in Hospital-Admitted Patients with COVID-19 in Egypt: A Single-Center Experience
149% worse results (p=0.03). Retrospective 236 hospitalized COVID-19 patients showing favipiravir use associated with increased risk of acute kidney injury (AKI). AKI was associated with higher mortality.
Dec 12
2024
 Siripongboonsitti et al., Journal of Virus Eradication, doi:10.1016/j.jve.2024.100576 Assessing Favipiravir's Impact on SARS-CoV-2 Transmission within Households: Insights from a Multi-center Study (FaviPrev)
25% lower transmission (p=0.05). Retrospective 976 mild to moderate COVID-19 outpatients in Thailand showing significantly lower household transmission with favipiravir treatment of index cases.
Nov 7
2024
 Prasanchaimontri et al., Pharmacology Research & Perspectives, doi:10.1002/prp2.1233 Favipiravir pharmacokinetics in Thai adults with mild COVID‐19: A sub‐study of interpatient variability and ethnic differences in exposure
Pharmacokinetic study of 8 Thai adults with mild COVID-19 showing higher favipiravir plasma concentrations compared to studies in other populations, suggesting regional/ethnic differences in pharmacokinetics. 7 of 8 adults achieved plasma..
Sep 14
2024
 Wawman et al., Respiratory infections and bronchiectasis, doi:10.1183/13993003.congress-2024.PA1507 Influence of demographics and dosing on COVID-19 outcomes and Favipiravir efficacy
Analysis of the Pioneer trial for favipiravir suggesting benefit in women and patients achieving target plasma concentrations. Only 17% of patients reached target plasma concentrations, with this subgroup showing trends toward improved ou..
Aug 31
2024
 Hobbs et al., Journal of Infection, doi:10.1016/j.jinf.2024.106248 Favipiravir for COVID-19 in adults in the community in PRINCIPLE, an open-label, randomised, controlled, adaptive platform trial of short- and longer-term outcomes
86% lower mortality (p=0.11), 1% lower combined mortality/hospitalization (p=0.51), and 17% improved recovery (p=0.003). RCT 3,622 (concurrent and eligible) COVID-19 outpatients in the UK showing significantly faster recovery with favipiravir, and significantly greater full recovery at 3, 6, and 12 months. Authors note: "From 16 Dec 2021, a minority of extr..
Aug 24
2024
 Duraníková et al., Journal of Clinical Medicine, doi:10.3390/jcm13175013 Prevalence and Risk Factors of Headache Associated with COVID-19
70% higher long COVID (p=0.24) and 45% worse results (p=0.14). Retrospective 295 hospitalized COVID-19 patients in Slovakia showing 35% prevalence of headache, of which 41% of patients had persistent headache 12-15 months after infection. Authors' analysis of long COVID headache is only for the subgr..
Jul 30
2024
 Shum, C., The University of Hong Kong, PhD Thesis An investigational study into the drug-associated mutational signature in SARS-CoV-2 viruses
In vitro and hamster study of drug associated SARS-CoV-2 mutations with several drugs including molnupiravir and favipiravir. Next-generation sequencing was used to identify de novo mutational spectra and single base substitution mutation..
Jul 26
2024
 Shiraki et al., Heliyon, doi:10.1016/j.heliyon.2024.e35331 Convenient screening of the reproductive toxicity of favipiravir and antiviral drugs in Caenorhabditis elegans
Reproductive toxicity analysis of antiviral drugs in C. elegans, showing increased incidence of arrested embryos with molnupiravir, favipiravir, ribavirin, acyclovir, ganciclovir, zidovudine, and thalidomide compared to controls. Authors ..
Jun 24
2024
 Lopez et al., Current Clinical Microbiology Reports, doi:10.1007/s40588-024-00229-6 SARS-CoV-2 Resistance to Small Molecule Inhibitors
Review of resistance mutations in SARS-CoV-2 3CLpro and nsp12 that could reduce efficacy of antiviral therapies including nirmatrelvir, ensitrelvir, remdesivir, and favipiravir. Authors identify 39 single mutations across 17 critical resi..
Jan 28
2024
 Saito et al., Infection Prevention in Practice, doi:10.1016/j.infpip.2024.100341 Predictors of in-hospital mortality in elderly unvaccinated patients during SARS-CoV-2 Alpha variants epidemic
168% higher mortality (p=0.06). Retrospective 132 hospitalized COVID-19 patients over age 65 in Japan during the Alpha variant surge, showing higher mortality with favipiravir in unadjusted results, without statistical significance.
Jan 8
2024
 Alsaraj et al., Infectious Diseases in Clinical Practice, doi:10.1097/IPC.0000000000001336 Consequence of Antivirals Versus Standard Care on Clinical Situation in Patients With COVID-19
87% higher mortality (p=0.26). RCT 156 COVID-19 patients showing higher mortality with favipiravir and remdesivir overall. Favipiravir and remdesivir were more effective when started earlier, however note that Table 10 compares earlier favipiravir/remdesivir+standard c..
Jan 4
2024
 Illingworth et al., Virus Evolution, doi:10.1093/ve/veae001 Genetic consequences of effective and suboptimal dosing with mutagenic drugs in a hamster model of SARS-CoV-2 infection
Syrian hamster study showing that short-term treatment with the mutagenic antiviral drugs favipiravir and molnupiravir led to increased genetic variation in SARS-CoV-2 viral populations. Treatment with effective antiviral doses resulted i..
Dec 29
2023
 Puriwatthanapong et al., Journal of Thai Traditional & Alternative Medicine, 21:3 Randomized-Controlled Trial to Compare the Efficacy of Andrographis paniculata Powder and Favipiravir for the Treatment of Mild COVID-19
RCT 231 mild COVID-19 outpatients in Thailand comparing Andrographis paniculata (AP) extract in two forms versus favipiravir, showing no significant differences between groups. Patients were randomized to either aerial parts AP extract (n..
Dec 6
2023
 Bacigalupo et al., Frontiers in Medicine, doi:10.3389/fmed.2023.1287542 Unveiling patenting strategies of therapeutics and vaccines: evergreening in the context of COVID-19 pandemic
Review of the patenting activity and evergreening approaches for three major COVID-19 antiviral medications - remdesivir, molnupiravir, and favipiravir. Authors found extensive primary and secondary patent filing, with 29 applications cov..
Dec 1
2023
 El-Fetouh et al., Journal of Advanced Veterinary Research, 13:10 Experimental Studies on Some Drugs Used in Covid-19 Treatment (Favipiravir and Dexamethasone) in Albino Rats
Animal study showing organ toxicity induced by favipiravir in rats. Histopathological and clinical results showed that favipiravir caused lesions in the liver, kidney and lung as well as increased liver enzymes, kidney function markers, o..
Nov 9
2023
 Erbaş et al., Journal of Biochemical and Molecular Toxicology, doi:10.1002/jbt.23536 Assessment of toxicological effects of favipiravir (T‐705) on the lung tissue of rats: An experimental study
Analysis of the toxicological effects of favipiravir on healthy lung tissue in rats. Authors found that favipiravir treatment increased oxidative stress, apoptosis, and inflammation in the lung tissue as evidenced by changes in antioxidan..
Oct 12
2023
 Iwata et al., Journal of Infection and Chemotherapy, doi:10.1016/j.jiac.2023.10.010 Findings from a discontinued clinical trial of favipiravir in high-risk patients with early-onset COVID-19
16% higher need for oxygen therapy (p=0.73) and 16% worse viral clearance (p=0.66). Early terminated RCT 84 patients in Japan, showing no significant difference in outcomes with favipiravir treatment. There was a trend for improved efficacy for patients enrolled within 48 hours of symptom onset.
Oct 7
2023
 Keleş, M., Master's Thesis COVID-19 hastalarında yüksek frekans odyometrisi sonuçlarının incelenmesi
High frequency audiometry in 40 individuals who had COVID-19, 21 treated with favipiravir, showing worse high frequency hearing for favipiravir patients, with statistical significance for right 14 kHz and left 12.5 kHz measurements, sugge..
Aug 24
2023
 Horcajada et al., Pneumonia, doi:10.1186/s41479-023-00124-6 (date from preprint) Safety and efficacy of favipiravir in COVID-19 patients with pneumonia. A randomized, double-blind, placebo-controlled study (FAVID)
383% higher mortality (p=0.49), 37% higher ventilation (p=1), no change in improvement (p=0.45), and 17% improved recovery (p=0.64). Underpowered RCT with 44 hospitalized patients in Spain, showing no significant difference with favipiravir treatment in the primary outcome of time to clinical improvement, or in the secondary efficacy outcomes. Adverse events were more ..
Jul 17
2023
 Shamsi et al., Canadian Journal of Infectious Diseases and Medical Microbiology, doi:10.1155/2023/5205188 Survival and Mortality in Hospitalized Children with COVID-19: A Referral Center Experience in Yazd, Iran
96% lower mortality (p=0.14). Retrospective 183 hospitalized pediatric COVID-19 patients in Iran, showing no significant difference in mortality with in unadjusted results.
Jun 14
2023
 Sulaiman et al., Journal of Infection and Public Health, doi:10.1016/j.jiph.2023.06.011 When Antivirals Backfire: An Evaluation of Favipiravir’s Clinical Outcomes in Critically Ill Patients with COVID-19: A Multicenter Cohort Study
17% higher mortality (p=0.51), 47% longer ventilation (p=0.008), and 50% longer ICU admission (p=0.01). PSM retrospective 1,218 COVID-19 ICU patients in Saudi Arabia, showing no significant difference in mortality, and longer ICU/MV time with favipiravir treatment.
Jun 1
2023
 Rudraraju et al., Stem Cell Reports, doi:10.1016/j.stemcr.2023.05.007 Parallel use of human stem cell lung and heart models provide insights for SARS-CoV-2 treatment
In vitro study showing that SARS-CoV-2 cell entry differs across cell types. ACE2 was required for infection in both lung and cardiac cells, but TMPRSS2 cleavage was required in lung cells, while the endosomal pathway was required in card..
May 24
2023
 Lokanuwatsatien et al., Frontiers in Pediatrics, doi:10.3389/fped.2023.1127582 Prevalence and associating factors of long COVID in pediatric patients during the Delta and the Omicron variants
14% lower long COVID (p=0.34). Prospective analysis of 802 COVID-19 pediatric patients in Thailand, showing no significant difference in long COVID with favipiravir treatment in unadjusted results.
May 4
2023
 Arfijanto et al., Pathophysiology, doi:10.3390/pathophysiology30020016 Duration of SARS-CoV-2 RNA Shedding Is Significantly Influenced by Disease Severity, Bilateral Pulmonary Infiltrates, Antibiotic Treatment, and Diabetic Status: Consideration for Isolation Period
51% improved viral clearance (p=0.02). Retrospective 162 hospitalized COVID-19 patients in Indonesia, showing lower incidence of delayed viral clearance with favipiravir treatment in unadjusted results.
Apr 5
2023
 Luvira et al., BMC Infectious Diseases, doi:10.1186/s12879-023-08835-3 (date from preprint) Clinical antiviral efficacy of favipiravir in early COVID-19 (PLATCOV): an open-label, randomised, controlled, adaptive platform trial
6% worse viral clearance (p=0.42). High conflict of interest RCT with very low risk patients, high existing immunity, and a post-hoc change to exclude patients more likely to benefit. There was no significant difference in viral clearance with favipiravir among patients wi..
Mar 21
2023
 Smith et al., NCT04918927 Favipiravir and/or Nitazoxanide: a Randomized, Double-blind, Placebo-controlled Trial of Early Antiviral Therapy in COVID-19 (FANTAZE)
120 patient favipiravir early treatment RCT with results not reported over 3 years after completion. The protocol has been published [trialsjournal.biomedcentral.com].
Mar 1
2023
 Irie, K., Yakugaku Zasshi, doi:10.1248/yakushi.22-00169-1 Pharmacokinetic Study of Antiviral Drugs in Patients with COVID-19
Pharmacokinetics study measuring the blood concentration of favipiravir in 7 critical patients in Japan, showing concentrations below the EC50 in 33 of 36 samples when using the standard dosing regimen. Authors note that patient character..
Feb 20
2023
 Almutairi et al., Tropical Medicine and Infectious Disease, doi:10.3390/tropicalmed8020129 Liver Injury in Favipiravir-Treated COVID-19 Patients: Retrospective Single-Center Cohort Study
Retrospective 362 COVID-19 patients showing significant liver injury in favipiravir-treated patients compared to untreated controls.
Feb 15
2023
 Alshamrani et al., Saudi Pharmaceutical Journal, doi:10.1016/j.jsps.2023.02.004 Comprehensive evaluation of six interventions for hospitalized patients with COVID-19: A propensity score matching study
14% higher mortality (p=0.13), 2% higher progression (p=0.83), 19% longer ICU admission (p=0.005), and 29% longer hospitalization (p=0.001). PSM retrospective 29 hospitals in Saudi Arabia, showing higher mortality with favipiravir treatment, without statistical significance.
Feb 9
2023
 Hartantri et al., The Lancet Regional Health - Southeast Asia, doi:10.1016/j.lansea.2023.100167 Clinical and treatment factors associated with the mortality of COVID-19 patients admitted to a referral hospital in Indonesia
76% lower mortality (p=0.0005). Retrospective 689 hospitalized patients in Indonesia, showing lower mortality with favipiravir treatment.
Jan 28
2023
 Vaezi et al., Advances in Respiratory Medicine, doi:10.3390/arm91010004 Favipiravir in the Treatment of Outpatient COVID-19: A Multicenter, Randomized, Triple-Blind, Placebo-Controlled Clinical Trial
105% higher hospitalization (p=0.43). RCT 77 outpatients in Iran, showing increased hospitalization with treatment, without statistical significance. Favipiravir 1600mg daily for five days. 21% of favipiravir patients did not complete treatment.
Jan 19
2023
 Alam et al., Preprints, doi:10.20944/preprints202301.0341.v1 Towards Predicting Length of Stay and Identification of Cohort Risk Factors Using Self-Attention Based Transformers and Association Mining: Covid-19 as Phenotype
Deep learning model for the prediction of hospitalization time for COVID-19 based on 311 patients in Saudi Arabia. Authors report shorter hospitalization time for HCQ and favipiravir, but do not provide details.
Jan 3
2023
 Gül et al., Sabuncuoglu Serefeddin Health Sciences, doi:10.55895/sshs.1213382 Effect of favipiravir use on INR, PT, aPTT tests of COVID-19 patients
Retrospective 100 patients in Turkey analyzing the effects of favipiravir on coagulation parameters in COVID-19 patients. Results showed prothrombin time (PT) and international normalized ratio (INR) were significantly prolonged in the fa..
Dec 31
2022
 Delen et al., Acta Clinica Croatica, doi:10.20471/acc.2022.61.03.05 Effects of Hydroxychloroquine Plus Favipiravir Treatment on the Clinical Course and Biomarkers in Hospitalized COVID-19 Patients with Pneumonia
88% improved recovery (p=0.02), 2% longer hospitalization (p=0.74), and 3% lower hospital discharge (p=1). Retrospective 69 COVID-19 patients in Turkey, showing improved fever recovery with the addition of favipiravir to HCQ, but no significant difference in discharge, ICU admission, or hospitalization time.
Nov 24
2022
 Alosaimi et al., Pharmaceuticals, doi:10.3390/ph15121456 Analyzing the Difference in the Length of Stay (LOS) in Moderate to Severe COVID-19 Patients Receiving Hydroxychloroquine or Favipiravir
80% lower mortality (p=0.49), 75% longer hospitalization (p=0.63), and 40% lower hospital discharge (p=0.74). Retrospective 200 hospitalized COVID-19 patients in Saudi Arabia, showing no significant difference in outcomes between HCQ and favipiravir.
Nov 11
2022
 Sitasuwan et al., Medicine, doi:10.1097/MD.0000000000031681 Early antiviral and supervisory dexamethasone treatment improve clinical outcomes of nonsevere COVID-19 patients
Retrospective 1,940 outpatients in Thailand, showing lower risk of clinical deterioration with early vs. late favipiravir treatment.
Nov 1
2022
 Chandiwana et al., eBioMedicine, doi:10.1016/j.ebiom.2022.104322 Safety and efficacy of four drug regimens versus standard-of-care for the treatment of symptomatic outpatients with COVID-19: A randomised, open-label, multi-arm, phase 2 clinical trial
13% higher progression (p=0.89), 23% slower recovery (p=0.42), and 67% worse viral clearance (p=0.13). High COI low-risk patient RCT in South Africa, showing no significant differences with favipiravir plus nitazoxanide. There were no deaths and no COVID-19 hospitalizations for favipiravir plus nitazoxanide. More patients were seropositive..
Sep 22
2022
 Shah et al., The Lancet Respiratory Medicine, doi:10.1016/S2213-2600(22)00412-X (date from preprint) Favipiravir in patients hospitalised with COVID-19 (PIONEER trial): a multicentre, open-label, phase 3, randomised controlled trial of early intervention versus standard care
26% lower mortality (p=0.24), 24% lower ventilation (p=0.21), and 6% improved recovery (p=0.53). PIONEER very late treatment RCT showing lower mortality and mechanical ventilation with favipiravir, without statistical significance. The conclusion "favipiravir is not efficacious in treating hospitalised adult patients with COVID-..
Sep 15
2022
 Behboodikhah et al., Iranian Journal of Science and Technology, Transactions A: Science, doi:10.1007/s40995-022-01351-0 Evaluation of the Costs and Outcomes of COVID-19 Therapeutic Regimens in Hospitalized Patients in Shiraz
68% lower mortality (p=0.2). Retrospective 2,174 hospitalized patients showing significantly shorter length of stay with favipiravir treatment.
Sep 10
2022
 Bruminhent et al., Tropical Medicine and Infectious Disease, doi:10.3390/tropicalmed7090238 Clinical Course and Outcomes among COVID-19 Patients at the Hospitel in Bangkok: A Retrospective Study
227% higher progression (p=0.005). Retrospective 514 patients in Thailand, showing higher risk of progression with favipiravir treatment.
Sep 6
2022
 Golan et al., Clinical Infectious Diseases, doi:10.1093/cid/ciac712 Favipiravir in patients with early mild-to-moderate COVID-19: a randomized controlled trial
2% lower progression (p=1), 4% improved recovery (p=0.79), and 14% faster viral clearance (p<0.0001). RCT low-risk (1 death in the control arm) patients in the USA, showing no significant differences with favipiravir. A majority of trial outcomes were modified after completion: [clinicaltrials.gov]. 44% of patients had no detectable viral..
Sep 5
2022
 Yildiz Pekoz et al., Drug Delivery, doi:10.1080/10717544.2022.2118398 Pulmonary delivery of favipiravir inhalation solution for COVID-19 treatment: in vitro characterization, stability, in vitro cytotoxicity, and antiviral activity using real time cell analysis
In vitro study of a favipiravir solution for inhalation, showing effective antiviral activity for SARS-CoV-2 with significantly lower doses than typically used with oral administration.
Aug 31
2022
 Babayigit et al., Frontiers in Medicine, doi:10.3389/fmed.2022.894126 The association of antiviral drugs with COVID-19 morbidity: The retrospective analysis of a nationwide COVID-19 cohort
184% higher ventilation (p=0.01), 181% higher ICU admission (p=0.001), and 100% longer hospitalization (p=0.001). Retrospective 1,472 hospitalized patients in Turkey, showing a higher ICU admission and ventilation with favipiravir. Results may be subject to confounding by indication.
Jun 29
2022
 Tawfik et al., Advances in Virology, doi:10.1155/2022/9240941 Effectiveness of Early Favipiravir Therapy in Hospitalised COVID-19 Patients
96% lower mortality (p<0.0001), 21% lower ICU admission (p=0.45), and 16% shorter hospitalization (p<0.0001). Retrospective 103 hospitalized patients in Saudi Arabia, showing lower mortality with favipiravir in unadjusted results, and greater efficacy for treatment within 3 days of admission.
Jun 28
2022
 Acar Sevinc, S., SiSli Etfal Hastanesi Tip Bulteni / The Medical Bulletin of Sisli Hospital, doi:10.14744/SEMB.2021.35902 Favipiravir Experience in COVID-19 Patients at a Tertiary Center Intensive Care Unit
16% lower mortality (p=0.38) and 10% lower ventilation (p=0.75). Retrospective 100 ICU patients in Turkey, showing improved survival with favipiravir vs. lopinavir/ritonavir.
Jun 21
2022
 Abdulrahman et al., Journal of Ayub Medical College Abbottabad, doi:10.55519/JAMC-03-10305 Favipiravir efficacy and safety for the treatment of severe coronavirus 2019: a retrospective study
3% lower mortality (p=0.81). Retrospective 1,699 ICU patients in Saudi Arabia, 193 treated with favipiravir, showing no significant difference in mortality.
Jun 15
2022
 Tehrani et al., Mediterranean Journal of Infection Microbes and Antimicrobials, doi:10.4274/mjima.galenos.2022.2022.30 Efficacy of Favipiravir in the Treatment of Moderate COVID-19 Patients: A Randomized, Open-label, Controlled Clinical Trial
34% lower hospitalization (p=0.24). RCT 78 patients in Iran, showing improved recovery with favipiravir treatment.
Jun 15
2022
 Rattanaumpawan et al., Antibiotics, doi:10.3390/antibiotics11060805 Real-World Effectiveness and Optimal Dosage of Favipiravir for Treatment of COVID-19: Results from a Multicenter Observational Study in Thailand
Retrospective 63 hospitalized patients in Thailand treated with favipiravir showing a lower favipiravir loading dose negatively associated with clinical improvement.
Jun 14
2022
 McMahon et al., eClinicalMedicine, doi:10.1016/j.eclinm.2022.101703 Favipiravir in early symptomatic COVID-19, a randomised placebo-controlled trial
1% higher need for oxygen therapy (p=1) and 56% higher hospitalization (p=0.38). RCT with 99 favipiravir and 100 placebo patients in Australia, all except one being outpatients, showing no significant differences with treatment.
Jun 8
2022
 Sirijatuphat et al., medRxiv, doi:10.1101/2022.06.06.22275902 Early Treatment of Favipiravir in COVID-19 Patients Without Pneumonia: A Multicentre, Open-Labelled, Randomized Control Study
64% faster improvement (p=0.0005), 43% lower progression (p=0.25), and 4% worse viral clearance (p=0.87). RCT 93 patients in Thailand showing significantly faster clinical improvement with favipiravir treatment. 1800mg favipiravir bid day 1, 800mg bid 5-14 days until PCR-.
Jun 7
2022
 Usanma Koban et al., Bratislava Medical Journal, doi:10.4149/BLL_2022_082 The factors affecting the prolonged PCR positivity in COVID-19 patients
86% improved viral clearance (p=0.03). Retrospective 126 patients in Turkey, showing lower risk of PCR+ at day 14 with favipiravir treatment.
May 23
2022
 Qadir et al., International Journal of Applied Sciences: Current and Future Research Trends, 13:1 Efficacy of Favipiravir in the Treatment of Mild to Moderate COVID-19 Patients in Erbil: A Controlled Clinical Trial
97% lower mortality (p<0.0001), 60% lower hospitalization (p=0.001), and 97% improved recovery (p<0.0001). Prospective study with 125 favipiravir patients and 125 patients declining favipiravir treatment, showing lower mortality and improved recovery with treatment. All patients received vitamin C, D, and zinc. Favipiravir 3200mg day 1, follow..
May 17
2022
 Lan et al., Expert Review of Clinical Pharmacology, doi:10.1080/17512433.2022.2078701 Favipiravir-based treatment for outcomes of patients with COVID-19: a systematic review and meta-analysis of randomized controlled trials
Systematic review and meta analysis of favipiravir RCTs, showing improved viral clearance and recovery, but no significant difference for mortality, ICU admission, or ventilation.
May 13
2022
 Rahman et al., Clinical Infection in Practice, doi:10.1016/j.clinpr.2022.100145 Safety and Efficacy of Favipiravir for the management of COVID-19 Patients: A Randomized Control Trial
89% greater improvement (p=0.005) and 92% improved viral clearance (p=0.0008). RCT hospitalized patients in Bangladesh, showing faster recovery and viral clearance with favipiravir treatment.
May 3
2022
 Reddy et al., International Journal of General Medicine, doi:10.2147/IJGM.S349241 Evaluation of the Safety and Efficacy of Favipiravir in Adult Indian Patients with Mild-to-Moderate COVID-19 in a Real-World Setting
Prospective single-arm study of 1,083 patients receiving favipiravir in India, showing one death and no new safety issues.
May 1
2022
 Mihaljevic et al., Mutagenesis, doi:10.1093/mutage/geac011 DNA damage in peripheral blood lymphocytes of severely ill COVID-19 patients in relation to inflammatory markers and parameters of hemostasis
Observational study of 24 severely ill hospitalized COVID-19 patients showing significantly higher DNA damage in peripheral blood lymphocytes compared to 15 healthy controls. Favipiravir was associated with increased DNA damage.
Apr 22
2022
 Hung et al., SSRN, doi:10.2139/ssrn.3889346 The efficacy and adverse effects of favipiravir on COVID-19 patients: a systematic review and meta-analysis of published clinical trials and observational studies
Systematic review and meta analysis of 17 favipiravir trials, showing improved viral clearance and recovery.
Apr 18
2022
 Hadj Hassine et al., Viruses, doi:10.3390/v14040841 Lethal Mutagenesis of RNA Viruses and Approved Drugs with Antiviral Mutagenic Activity
Review of lethal mutagenesis for RNA viruses, as used by molnupiravir, favipiravir, and ribavirin. Authors note the potential for permanently modifying the genomes of patients while causing teratogenicity or embryotoxicity, and the potent..
Apr 8
2022
 Hafez et al., Antibiotics, doi:10.3390/antibiotics11040498 Antiviral Used among Non-Severe COVID-19 Cases in Relation to Time till Viral Clearance: A Retrospective Cohort Study
3% slower viral clearance (p=0.09). Retrospective hospitalized patients in the United Arab Emirates, showing no significant difference in viral clearance with different combinations of HCQ, AZ, favipiravir, and lopinavir/ritonavir.
Mar 24
2022
 Shinada et al., Viruses, doi:10.3390/v14040670 Longitudinal Analysis of Neutralizing Potency against SARS-CoV-2 in the Recovered Patients after Treatment with or without Favipiravir
7% shorter hospitalization (p=0.84) and 55% faster viral clearance (p=0.04). Retrospective 17 COVID+ patients treated with favipiravir and 17 matched controls in Japan, showing faster viral clearance with treatment. Favipiravir 3600mg day one, 1600mg per day for up to 14 days.
Mar 23
2022
 AlQahtani et al., Scientific Reports, doi:10.1038/s41598-022-08794-w Randomized controlled trial of favipiravir, hydroxychloroquine, and standard care in patients with mild/moderate COVID-19 disease
76% lower ICU admission (p=0.2), 42% worse recovery (p=0.51), and 43% improved viral clearance (p=0.21). RCT with 54 favipiravir, 51 HCQ, and 52 SOC hospitalized patients in Bahrain, showing no significant differences. Viral clearance improved with both treatments, but did not reach statistical significance with the small sample size.
Mar 21
2022
 Tsuzuki et al., Infectious Diseases and Therapy, doi:10.1007/s40121-022-00617-9 Effectiveness of Favipiravir on Nonsevere, Early-Stage COVID-19 in Japan: A Large Observational Study Using the COVID-19 Registry Japan
13% lower mortality (p=0.59), 2% higher ventilation (p=0.93), and 18% lower progression (p=0.1). Retrospective database analysis of 7,654 hospitalized patients in Japan, showing no significant differences with favipiravir treatment. NCGM-G-003494-0.
Mar 17
2022
 Uyaroğlu et al., Acta Medica, doi:10.32552/2022.ActaMedica.719 Comparison of Favipiravir to Hydroxychloroquine Plus Azithromycin in the Treatment of Patients with Non-critical COVID-19: A Single-center, Retrospective, Propensity Score-matched Study
67% lower mortality (p=1), 200% higher ICU admission (p=1), and 11% longer hospitalization (p=0.9). PSM retrospective 260 late stage hospitalized COVID-19 pneumonia patients in Turkey, showing no significant difference between favipiravir and HCQ.
Mar 24
2022
 Hassaniazad et al., Journal of Medical Virology, doi:10.1002/jmv.27724 Efficacy and safety of favipiravir plus interferon-beta versus lopinavir/ritonavir plus interferon-beta in moderately ill patients with COVID-19: A randomized clinical trial
68% lower mortality (p=0.15), 35% lower ICU admission (p=0.51), 25% shorter hospitalization (p=0.14), and 18% improved viral clearance (p=0.24). RCT comparing favipiravir and lopinavir/ritonavir, showing no significant differences. All patients received interferon-beta. Favipiravir 1600mg bid for the first day and 600mg bid for the following 4 days.
Mar 7
2022
 Yulia et al., Pathophysiology, doi:10.3390/pathophysiology29010009 Evaluation of Antibacterial and Antiviral Drug Effectiveness in COVID-19 Therapy: A Data-Driven Retrospective Approach
85% lower mortality (p=0.05). Retrospective hospitalized patients in Indonesia, showing lower mortality and shorter hospitalization with favipiravir.
Mar 4
2022
 Al-Muhsen et al., Frontiers in Medicine, doi:10.3389/fmed.2022.826247 Favipiravir Effectiveness and Safety in Hospitalized Moderate-Severe COVID-19 Patients: Observational Prospective Multicenter Investigation in Saudi Arabia
263% higher mortality (p=0.04), 41% lower need for oxygen therapy (p<0.0001), and 40% longer hospitalization (p=0.03). Prospective observational study of 598 hospitalized patients in Saudi Arabia, showing higher risk of mortality and longer hospitalization time with favipiravir.
Mar 3
2022
 Cilli et al., Respiratory Medicine and Research, doi:10.1016/j.resmer.2022.100900 Characteristics and outcomes of COVID-19 patients with IPF: A multi-center retrospective study
38% lower mortality (p=0.51). Retrospective 46 idiopathic pulmonary fibrosis patients with COVID-19 in Turkey, showing lower mortality with favipiravir in unadjusted results, without statistical significance.
Mar 1
2022
 Adhikari et al., International Journal of Infectious Diseases, doi:10.1016/j.ijid.2021.12.109 Efficacy of Favipiravir in treatment of mild & moderate COVID-19 infection in Nepal: a multi-center, randomized, open-labelled, phase III clinical trial
40% worse improvement (p=0.57). Preliminary report for an RCT in Nepal with 38 favipiravir patients and 32 control patients, showing no significant differences. There were no serious side effects.
Feb 28
2022
 Kurniyanto et al., Journal of Clinical Virology Plus, doi:10.1016/j.jcvp.2022.100068 Factors Associated with Death and ICU Referral among COVID-19 Patients Hospitalized in the Secondary Referral Academic Hospital in East Jakarta, Indonesia
48% lower mortality (p=0.21). Retrospective 477 hospitalized patients in Indonesia, showing lower mortality with favipiravir in unadjusted results, not reaching statistical significance.
Feb 15
2022
 Al Mutair et al., Journal of Infection and Public Health, doi:10.1016/j.jiph.2022.01.013 Overview of Clinical Outcome and Therapeutic Effectiveness of Favipiravir in Patients with COVID-19 Admitted to Intensive Care Unit, Riyadh, Saudi Arabia
7% lower mortality (p=0.49), 9% higher ARDS (p=0.63), 34% longer ICU admission (p=0.001), and 37% longer hospitalization (p=0.001). Retrospective 269 favipiravir ICU patients in Saudi Arabia and 269 matched controls receiving different treatments, showing no significant difference.
Feb 15
2022
 Lowe et al., PLOS Medicine, doi:10.1371/journal.pmed.1004120 (date from preprint) Favipiravir, lopinavir-ritonavir, or combination therapy (FLARE): A randomised, double-blind, 2 × 2 factorial placebo-controlled trial of early antiviral therapy in COVID-19
28% improved viral clearance (p=0.03). 240 patient RCT comparing favipiravir, favipiravir + LPV/r, LPV/r, and placebo, showing improved viral clearance with favipiravir, but no significant difference for LPV/r. Efficacy was lower in the combined favipiravir + LPV/r arm, where ..
Feb 1
2022
 Turan et al., The Brazilian Journal of Infectious Diseases, doi:10.1016/j.bjid.2022.102328 The effect of favipiravir versus hydroxychloroquine on clinical and laboratory findings in COVID-19 in healthcare workers
79% lower hospitalization (p=0.001), 11% slower recovery (p=0.51), and 22% faster viral clearance (p=0.001). Retrospective 237 low-risk healthcare workers in Turkey, 123 treated with favipiravir and 114 treated with HCQ, showing lower hospitalization and faster viral clearance with favipiravir, and similar improvement. This study is subject to s..
Jan 28
2022
 Waters et al., Environmental and Molecular Mutagenesis, doi:10.1002/em.22471 Human genetic risk of treatment with antiviral nucleoside analog drugs that induce lethal mutagenesis: the special case of molnupiravir
Review of antiviral nucleoside analog drugs that induce lethal mutagenesis, including molnupiravir and favipiravir, and the potential mutagenic risks to human DNA and human mitochondrial DNA. Author recommends monitoring for mutagenicity,..
Jan 12
2022
 Unal et al., bioRxiv, doi:10.1101/2022.01.11.475889 Favipiravir, umifenovir and camostat mesylate: a comparative study against SARS-CoV-2
In vitro and in silico study showing that the combination of favipiravir and umifenovir or camostat mesylate has greater antiviral efficacy than single drug treatment.
Jan 11
2022
 Bosaeed et al., Clinical Microbiology and Infection, doi:10.1016/j.cmi.2021.12.026 Efficacy of favipiravir in adults with mild COVID-19: a randomized, double-blind, multicenter, placebo-controlled trial clinical trial
619% higher ICU admission (p=0.11), 219% higher hospitalization (p=0.16), 12% slower recovery (p=0.51), and 15% slower viral clearance (p=0.51). RCT with 112 favipiravir and 119 control patients showing no significant differences in outcomes. Viral clearance and clinical recovery for patients treated within 48 hours was better than those treated later. NCT04464408.
Dec 7
2021
 Finberg et al., Open Forum Infectious Diseases, doi:10.1093/ofid/ofab56310 US201 Study: A Phase 2, Randomized Proof-of-Concept Trial of Favipiravir for the Treatment of COVID-19
20% longer hospitalization, 58% improved recovery (p=0.08), and 47% faster viral clearance (p=0.04). Small very late treatment RCT in the USA, with 25 favipiravir and 25 control patients, showing faster viral clearance with treatment. The benefit was only seen in patients <8 days from symptom onset. There were no significant differences ..
Nov 30
2021
 Alattar et al., Journal of Infection and Public Health, doi:10.1016/j.jiph.2022.08.011 (date from preprint) Favipiravir for the Treatment of Coronavirus Disease 2019 Pneumonia; a Propensity Score-matched Cohort Study
33% lower mortality (p=0.5), 2% worse recovery (p=0.73), and 44% improved viral clearance (p<0.0001). PSM retrospective with 1,493 patients, showing significantly improved viral clearance with favipiravir. There were no significant differences in clinical improvement or mortality. Mortality was lower (2.1% vs 3.1%), without statistical si..
Nov 24
2021
 Holubar et al., Clinical Infectious Diseases, doi:10.1093/cid/ciac312 (date from preprint) Favipiravir for treatment of outpatients with asymptomatic or uncomplicated COVID-19: a double-blind randomized, placebo-controlled, phase 2 trial
89% lower hospitalization (p=0.06), 30% lower progression (p=0.56), 19% worse recovery (p=0.43), and 32% worse viral clearance (p=0.24). Small RCT 116 mITT patients in the USA, 59 treated with favipiravir, showing no significant differences with treatment.
Nov 19
2021
 Chuah et al., Clinical Infectious Diseases, doi:10.1093/cid/ciab962 Efficacy of Early Treatment with Favipiravir on Disease Progression among High Risk COVID-19 Patients: A Randomized, Open-Label Clinical Trial
1154% higher mortality (p=0.08), 20% higher ventilation (p=0.76), and 9% higher ICU admission (p=0.84). RCT 500 hospitalized patients in Malaysia, showing no significant differences with favipiravir treatment.
Nov 9
2021
 Shenoy et al., medRxiv, doi:10.1101/2021.11.08.21265884 Favipiravir In Adults with Moderate to Severe COVID-19: A Phase 3 Multicentre, Randomized, Double-Blind, Placebo-Controlled Trial
29% higher mortality (p=0.54), 33% higher ventilation (p=0.54), 2% higher ICU admission (p=0.54), and 1% slower recovery (p=0.94). Late stage RCT with 353 hospitalized patients, showing no significant differences with favipiravir treatment overall, however a trend towards benefit was seen within patients treated relatively early, including a statistically significant..
Nov 1
2021
 Damayanti et al., Kesmas: National Public Health Journal, doi:10.21109/kesmas.v16i4.5433 The Effectiveness and Safety of Favipiravir in COVID-19 Hospitalized Patients in Bali, Indonesia
54% improved recovery (p=0.03). Retrospective 192 hospitalized patients in Indonesia, 96 patients treated with favipiravir, showing improved recovery with treatment. Only the abstract is currently available.
Oct 5
2021
 Atipornwanich et al., SSRN Electronic Journal, doi:10.2139/ssrn.3936499 Various Combinations of Favipiravir, Lopinavir-Ritonavir, Darunavir-Ritonavir, High-Dose Oseltamivir, and Hydroxychloroquine for the Treatment of COVID-19: A Randomized Controlled Trial (FIGHT-COVID-19 Study)
23% lower mortality (p=0.66), 60% lower progression (p=0.009), and 9% faster viral clearance (p=0.43). RCT 200 moderate/severe patients in Thailand, showing significantly lower progression with favipiravir vs. oseltamivir. This paper contains multiple data issues and the preprint has not been published in a journal. The manuscript title an..
Sep 30
2021
 Tabarsi et al., Iranian Journal of Pharmaceutical Research, doi:10.22037/ijpr.2021.115510.15401 Favipiravir Effects on the Control of Clinical Symptoms of Hospitalized COVID-19 Cases: An Experience with Iranian Formulated Dosage Form
41% lower ICU admission (p=0.36), 6% improved recovery (p=0.76), and 25% shorter hospitalization (p=0.03). Small 62 patient late stage RCT in Iran comparing favipiravir and lopinavir/ritonavir, showing significant improvement in fever, cough, and dyspnea with favipiravir on day 5. There was no significant difference in mortality, ICU admission..
Sep 14
2021
 Alotaibi et al., International Journal of General Medicine, 2021:14 Effectiveness and Safety of Favipiravir Compared to Hydroxychloroquine for Management of Covid-19: A Retrospective Study
57% lower mortality (p=0.05). Retrospective hospitalized patients in Saudi Arabia, showing lower mortality with favipiravir compared to HCQ, not quite reaching statistical significance. Authors do not indicate the factors behind which therapy was chosen. May be subjec..
Sep 9
2021
 Sawanpanyalert et al., Southeast Asian Journal of Tropical Medicine and Public Health, 52:4 Assessment of outcomes following implementation of antiviral treatment guidelines for COVID-19 during the first wave in Thailand
68% lower progression (p=0.003). Retrospective 744 hospitalized patients in Thailand, showing lower risk of a poor outcome for favipiravir treatment within 4 days of symptom onset. Early treatment with CQ/HCQ and lopinavir/ritonavir or darunavir/ritonavir also showed low..
Sep 2
2021
 Chen et al., Frontiers in Pharmacology, doi:10.3389/fphar.2021.683296 Favipiravir Versus Arbidol for Clinical Recovery Rate in Moderate and Severe Adult COVID-19 Patients: A Prospective, Multicenter, Open-Label, Randomized Controlled Clinical Trial
74% lower progression (p=0.37), 20% lower need for oxygen therapy (p=0.42), and 20% improved recovery (p=0.15). Very late stage (9 days from symptom onset) RCT with 116 favipiravir patients and 120 arbidol patients in China, showing no significant difference in clinical recovery (relief of fever and cough, respiratory frequency ≤24 times/min, and o..
Aug 31
2021
 Kulzhanova et al., Clinical efficacy of the antiviral drug favipiravir in the complex treatment of patients with COVID-19 coronavirus infection
88% greater improvement (p<0.0001) and 50% improved viral clearance (p=0.18). Retrospective 40 favipiravir patients in Kazakhstan and 40 controls, showing faster recovery and viral clearance with treatment.
Aug 28
2021
 Assiri et al., Journal of Infection and Public Health, doi:10.1016/j.jiph.2021.08.030 COVID-19 related treatment and outcomes among COVID-19 ICU patients: A retrospective cohort study
79% higher mortality (p=0.5). Retrospective 118 ICU patients in Saudi Arabia showing no significant differences in unadjusted results with zinc, vitamin D, and favipiravir treatment. This paper has several data issues: The text states the outcome variable was coded as..
Aug 27
2021
 Shinkai et al., Infectious Diseases and Therapy, doi:10.1007/s40121-021-00517-4 Efficacy and Safety of Favipiravir in Moderate COVID-19 Pneumonia Patients without Oxygen Therapy: A Randomized, Phase III Clinical Trial
37% faster recovery (p=0.01). RCT 156 patients in Japan, 107 treated with favipiravir, showing significant improvement in a composite outcome defined as the time to improvement in temperature, SpO2, CT findings, and recovery to PCR-.
Aug 24
2021
 Almoosa et al., Journal of Infection and Public Health, doi:10.1016/j.jiph.2021.08.022 Favipiravir versus Standard of Care in Patients with Severe COVID-19 Infections: A Retrospective Comparative Study
42% higher mortality (p=0.1), 90% higher ICU admission (p=0.02), and 11% slower recovery (p=0.17). Retrospective 226 COVID-19 pneumonia patients, 110 treated with favipiravir, showing higher mortality (p=0.1) and ICU admission (p=0.02) with treatment in multivariate analysis.
Jun 18
2021
 Purwati et al., PLOS One, doi:10.1371/journal.pone.0252302 An in vitro study of dual drug combinations of anti-viral agents, antibiotics, and/or hydroxychloroquine against the SARS-CoV-2 virus isolated from hospitalized patients in Surabaya, Indonesia
In vitro study of combinations of drugs showing antiviral efficacy of HCQ alone and in combination with AZ, favipiravir, and doxycycline. No high levels of cytotoxicity were observed, and authors conclude that using a combination of drugs..
Jun 1
2021
 Kara et al., NCT04411433 Efficacy and Safety of Hydroxychloroquine and Favipiravir in the Treatment of Mild to Moderate COVID-19
1,008 patient favipiravir early treatment RCT with results not reported over 5 years after completion.
May 19
2021
 Alamer et al., Current Medical Research and Opinion, doi:10.1080/03007995.2021.1920900 Effectiveness and safety of favipiravir compared to supportive care in moderately to critically ill COVID-19 patients: a retrospective study with propensity score matching sensitivity analysis
56% higher mortality (p=0.26), 90% lower ventilation (p<0.0001), and 49% higher hospital discharge (p<0.0001). Retrospective 234 favipiravir and 223 control patients in Saudi Arabia, showing shorter time to discharge and lower progression to ventilation, but no significant difference in mortality.
May 5
2021
 Zhirnov et al., Journal of microbiology, epidemiology and immunobiology, doi:10.36233/0372-9311-114 Favipiravir: the hidden threat of mutagenic action
Review of the mutagenic effect of favipiravir and associated concerns.
Apr 29
2021
 Haji Aghajani et al., Journal of Medical Virology, doi:10.1002/jmv.27053 Decreased In-Hospital Mortality Associated with Aspirin Administration in Hospitalized Patients Due to Severe COVID-19
26% lower mortality (p=0.28). Retrospective 991 hospitalized patients in Iran focusing on aspirin use but also showing results for HCQ, remdesivir, and favipiravir.
Apr 28
2021
 Kokturk et al., Respiratory Medicine, doi:10.1016/j.rmed.2021.106433 The predictors of COVID-19 mortality in a nationwide cohort of Turkish patients
84% higher mortality (p=0.29). Retrospective 1,500 hospitalized late stage (median SaO2 87.7) patients in Turkey, showing no significant difference in mortality with treatment.
Apr 21
2021
 Zhao et al., International Immunopharmacology, doi:10.1016/j.intimp.2021.107702 Favipiravir in the treatment of patients with SARS-CoV-2 RNA recurrent positive after discharge: a multicenter, open-label, randomized trial
59% improved viral clearance (p=0.06). RCT with 55 patients (36 favipiravir, 19 control) who were PCR+ after recovery, showing improved viral clearance with treatment.
Apr 19
2021
 Favipiravir Observational Study Group, Fujita Health University Favipiravir Observational Study Interim Report 3
Retrospective analysis of favipiravir use in 10,986 hospitalized patients, including analysis of changes in clinical status and side effects. Common adverse events were uric acid level increase and liver function enzyme increase. Authors ..
Apr 17
2021
 Fujii et al., Journal of Infection and Chemotherapy, doi:10.1016/j.jiac.2021.04.013 Early favipiravir treatment was associated with early defervescence in non-severe COVID-19 patients
Retrospective 41 favipiravir patients finding that early treatment was more successful.
Mar 11
2021
 Solaymani-Dodaran et al., International Immunopharmacology, doi:10.1016/j.intimp.2021.107522 Safety and efficacy of Favipiravir in moderate to severe SARS-CoV-2 pneumonia
19% higher mortality (p=0.54), 53% higher ventilation (p=0.15), and 19% higher ICU admission (p=0.56). RCT late stage patients (median SpO2 89), 193 treated with favipiravir, 187 with lopinavir/ritonavir, showing no significant differences in mortality, intubation, or ICU admission.
Mar 8
2021
 Fateh et al., medRxiv, doi:10.1101/2021.03.05.21251351 A single-center retrospective cohort study of Covid-19 medications: Remdesivir, Favipiravir, Methylprednisolone, Dexamethasone, and Interferon β1a and their combinations
Retrospective 324 hospitalized patients in Iran reporting on the use remdesivir, favipiravir, methylprednisolone, dexamethasone, and Interferon β1a and their combinations. There is no control group in this study.
Feb 4
2021
 Uçan et al., Research Square, doi:10.21203/rs.3.rs-175340/v1 Benefits of Treatment With Favipiravir in Hospitalized Patients for COVID-19: a Retrospective Observational Case-control Study
Retrospective 144 COVID-19 patients in Turkey, one group receiving FPV after a mean of 4.7 days, a second group after a mean of 8.6 days, and all groups receiving HCQ. No improvement in clinical outcomes was seen with the addition of FPV,..
Jan 25
2021
 Dabbous et al., Archives of Virology, doi:10.1007/s00705-021-04956-9 RETRACTED: Efficacy of favipiravir in COVID-19 treatment: a multi-center randomized study
This study was retracted.
Jan 14
2021
 Karatas et al., Research Square, doi:10.21203/rs.3.rs-142868/v1 Early Onset Favipiravir Saves Lives
Retrospective 180 hospitalized patients showing lower mortality when Favipiravir is given earlier. 17% of patients given Favipiravir within 3 days died, compared to 38% when given after 3 days.
Nov 17
2020
 Doi et al., Antimicrobial Agents and Chemotherapy, doi:10.1128/AAC.01897-20 A Prospective, Randomized, Open-Label Trial of Early versus Late Favipiravir Therapy in Hospitalized Patients with COVID-19
Small RCT comparing late and very late (7 and 14 days from fever onset) favipiravir. Viral clearance was non-statistically significantly improved with relatively early treatment. There was a reduction in time to defervescence, and a signi..
Nov 16
2020
 Udwadia et al., International Journal of Infectious Diseases, doi:10.1016/j.ijid.2020.11.142 Efficacy and Safety of Favipiravir, an Oral RNA-Dependent RNA Polymerase Inhibitor, in Mild-to-Moderate COVID-19: A Randomized, Comparative, Open-Label, Multicenter, Phase 3 Clinical Trial
29% faster recovery (p=0.07) and 27% faster viral clearance (p=0.1). RCT with 75 favipiravir patients and 75 control patients showing improved recovery with treatment.
Nov 9
2020
 Khamis et al., International Journal of Infectious Diseases, doi:10.1016/j.ijid.2020.11.008 Randomized Controlled Open Label Trial on the Use of Favipiravir Combined with Inhaled Interferon beta-1b in Hospitalized Patients with Moderate to Severe COVID-19 Pneumonia
15% lower mortality (p=1), 2% higher ICU admission (p=1), and 10% worse recovery (p=0.82). Small 89 patient RCT comparing favipiravir and inhaled interferon with HCQ for moderate to severe COVID-19 pneumonia, not finding significant differences. There was no control group.
Nov 5
2020
 Pushkar et al., NCT04542694 Study of Favipiravir Compared to Standard of Care in Hospitalized Patients With COVID-19
14% improved recovery (p=0.06), 70% higher hospital discharge (p=0.0001), 33% lower pneumonia (p=0.007), and 90% improved viral clearance (p<0.0001). RCT 200 patients showing improvements in clinical recovery and viral clearance with favipiravir. There is no paper available but results are posted in clinicaltrials.gov.
Oct 26
2020
 Ruzhentsova et al., SSRN, doi:10.2139/ssrn.3696907 Phase 3 Trial of Coronavir (Favipiravir) in Patients with Mild to Moderate COVID-19
39% faster recovery (p=0.007) and 22% improved viral clearance (p=0.16). RCT 168 patients, 112 receiving favipiravir and 56 SOC, showing shorter time to clinical improvement and faster viral clearance with favipiravir.
Oct 25
2020
 Lou et al., European Journal of Pharmaceutical Sciences, doi:10.1016/j.ejps.2020.105631 Clinical Outcomes and Plasma Concentrations of Baloxavir Marboxil and Favipiravir in COVID-19 Patients: An Exploratory Randomized, Controlled Trial
422% higher ICU admission (p=0.21), 11% improved recovery (p=1), and 422% worse viral clearance (p=0.21). Small late stage RCT with 10 favipiravir, 10 baloxavir marboxil, and 10 control patients in China, showing no significant differences.
Sep 30
2020
 Zhao et al., Biomedicine & Pharmacotherapy, doi:10.1016/j.biopha.2020.110825 Tocilizumab combined with favipiravir in the treatment of COVID-19: A multicenter trial in a small sample size
Small study with 14 combined favipiravir/tocilizumab, 7 favipiravir, and 5 tocilizumab patients suggesting that tocilizumab combined with or without favipiravir can improve pulmonary inflammation and inhibit progression.
Aug 9
2020
 Ivashchenko et al., Clinical Infectious Diseases, doi:10.1093/cid/ciaa1176 AVIFAVIR for Treatment of Patients with Moderate COVID-19: Interim Results of a Phase II/III Multicenter Randomized Clinical Trial
46% improved viral clearance (p=0.03) and 67% lower hospital discharge (p=0.51). Interim results for a small RCT with 40 favipiravir and 20 control patients showing faster viral clearance with favipiravir. There is limited data in this report to evaluate the results. 75% of the control group received HCQ/CQ.
Jun 19
2020
 Kaptein et al., bioRxiv, doi:10.1101/2020.06.19.159053 Favipiravir at high doses has potent antiviral activity in SARS-CoV-2−infected hamsters, whereas hydroxychloroquine lacks activity
Animal study with Syrian hamsters, showing antiviral activity with favipiravir.
Mar 18
2020
 Cai et al., Engineering, doi:10.1016/j.eng.2020.03.007 Experimental Treatment with Favipiravir for COVID-19: An Open-Label Control Study
69% lower pneumonia (p=0.04) and 71% improved viral clearance (p=0.03). Comparison of 35 FPV patients and 35 LPV/RTV patients, showing significant improvements in chest CT and faster viral clearance with FPV.
References