Add-on favipiravir brightens outlook for hospitalized COVID-19 patients

When used in addition to standard of care, favipiravir leads to faster viral clearance and clinical improvement time among patients hospitalized with COVID-19, although it appears to contribute to an increased risk of hyperuricaemia, according to the results of a meta-analysis

Researchers performed a systematic review of studies that evaluated the efficacy of favipiravir in COVID-19 patients. They searched multiple online databases and identified 157 studies (24 randomized controlled trials [RCTs], one non-RCT, 21 observational studies, two case series, and 106 case reports) for inclusion in the meta-analysis.

Pooled data revealed that when compared with the standard of care alone, the addition of favipiravir was associated with a significantly higher rate of viral clearance at day 5 (risk ratio [RR], 1.60; p=0.02), defervescence at day 3–4 (RR, 1.99; p<0.01), chest radiological improvement (RR, 1.33; p<0.01), hospital discharge at day 10–11 (RR, 1,19; p<0.01), and shorter clinical improvement time (mean difference [MD], –1.18; p=0.05).

In terms of safety, patients who received add-on favipiravir more commonly developed hyperuricaemia (RR, 9.42; p<0.01) and increased alanine aminotransferase (RR, 1.35; p<0.01). Meanwhile, they had lower rates of nausea (RR, 0.42; p<0.01) and vomiting (RR, 0.19; p=0.02). There were no significant between-group differences in mortality (RR, 1.19; p=0.32) and aspartate aminotransferase elevation (RR, 1.11; p=0.25).

In COVID-19 outpatients, the addition of favipiravir did not significantly alter the outcomes as compared with the standard of care alone.

The findings suggest that adding favipiravir to the standard of care may improve outcomes for hospitalized patients but not for outpatients. Hyperuricaemia should also be noted when using the drug for prompt treatment cessation. Further caution should be applied when administrating favipiravir to pregnant or lactating women due to its probable teratogenic effects.