Molnupiravir for treating COVID-19.

Summary

This Cochrane review synthesizing 11 RCTs (31,272 participants) found that in outpatients with mild-to-moderate COVID-19, molnupiravir probably results in little to no reduction in all-cause mortality and may not reduce hospitalization, despite higher early viral clearance. Adverse and serious adverse events were similar to control. Evidence in inpatients remains unclear due to heterogeneity.

Key Findings

• Across 7 outpatient RCTs (29,238 participants), all-cause mortality at 28–30 days showed little to no difference (RR 0.17, 95% CI 0.04–0.65; absolute reduction ~9 per 10,000).
• Hospitalization may not be reduced (RR 0.70, 95% CI 0.43–1.12); symptom resolution by days 14 or 28 showed little to no difference.
• Viral clearance was higher by day 5 (RR 3.40) but attenuated by day 10 and largely absent by day 14–15; safety profiles were similar with little to no difference in serious adverse events.

Clinical Implications

Molnupiravir should be deprioritized for outpatients with mild-to-moderate COVID-19 given minimal effects on mortality and hospitalization; resources should favor agents with demonstrated clinical benefit in current variants. Early viral clearance alone should not guide treatment decisions.

Limitations

• Heterogeneity in vaccination status and circulating variants; inpatient data too heterogeneous for meta-analysis
• Potential publication bias with multiple unpublished trials; clinical relevance of late viral clearance uncertain

Future Directions

Focus on head-to-head comparisons of oral antivirals against current variants, stratified by risk/vaccination; clarify inpatient effectiveness and variant-specific outcomes.