Amantadine: meta-analysis of COVID-19 studies

All studies Mortality ICU Hospitalization Serious outcomes Recovery RCTs RCT mortality Peer-reviewed All outcomes

Outcome (studies)

Improvement

Relative risk · 95% CI

All studies (3)−19%

Mortality (2)0%

ICU admission (1)18%

Hospitalization (1)−67%

Recovery (2)5%

RCTs (3)−19%

RCT mortality (2)0%

Late (3)−19%

00.511.5+

← Amantadine
reduces riskIncreased
risk →

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c19early.org

October 2026

Amantadine COVID-19 studies

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Barczyk (DB RCT)−13%1.13 · 0.40–3.23death95 (n)91 (n) Rejdak (DB RCT)66%0.34 · 0.01–8.04death0/491/50 Weis (DB RCT)−67%1.67 · 0.41–6.82hosp.5/1213/121ACT

Late treatment−19%1.19 · 0.53–2.675/2654/26219% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.69

All studies−19%1.19 · 0.53–2.675/2654/26219% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.6900.511.52+

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← Amantadine
reduces riskAmantadine
increases risk →

c19early.org

October 2026

Amantadine COVID-19 mortality results

StudyImprovementRR · 95% CITreatmentControlRelative Risk

Barczyk (DB RCT)−13%1.13 · 0.40–3.2395 (n)91 (n) Rejdak (DB RCT)66%0.34 · 0.01–8.040/491/50

Late treatment0%1.00 · 0.37–2.710/1441/1410% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.99

All studies0%1.00 · 0.37–2.710/1441/1410% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.9900.511.52+

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reduces riskAmantadine
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c19early.org

October 2026

Amantadine COVID-19 ICU results

StudyImprovementRR · 95% CITreatmentControlRelative Risk

Barczyk (DB RCT)18%0.82 · 0.26–2.5595 (n)91 (n)

Late treatment18%0.82 · 0.26–2.5795 (n)91 (n)18% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.75

All studies18%0.82 · 0.26–2.5795 (n)91 (n)18% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.7500.511.52+

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← Amantadine
reduces riskAmantadine
increases risk →

c19early.org

October 2026

Amantadine COVID-19 hospitalization results

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Weis (DB RCT)−67%1.67 · 0.41–6.82hosp.5/1213/121ACT

Late treatment−67%1.67 · 0.41–6.825/1213/12167% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.49

All studies−67%1.67 · 0.41–6.825/1213/12167% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.4900.511.52+

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← Amantadine
reduces riskAmantadine
increases risk →

c19early.org

October 2026

Amantadine COVID-19 serious outcomes

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Barczyk (DB RCT)−13%1.13 · 0.40–3.23death95 (n)91 (n) Rejdak (DB RCT)66%0.34 · 0.01–8.04death0/491/50 Weis (DB RCT)−67%1.67 · 0.41–6.82hosp.5/1213/121ACT

Late treatment−19%1.19 · 0.53–2.675/2654/26219% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.69

All studies−19%1.19 · 0.53–2.675/2654/26219% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.6900.511.52+

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← Amantadine
reduces riskAmantadine
increases risk →

c19early.org

October 2026

Amantadine COVID-19 recovery results

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Rejdak (DB RCT)39%0.61 · 0.40–0.94no recov.18/4930/50 Weis (DB RCT)−48%1.48 · 0.95–2.30no recov.37/12125/121ACT

Late treatment5%0.95 · 0.40–2.2655/17055/1715% lower risk

Tau² = 0.34, I² = 87.3%, p = 0.92

All studies5%0.95 · 0.40–2.2655/17055/1715% lower risk

Tau² = 0.34, I² = 87.3%, p = 0.9200.511.52+

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← Amantadine
reduces riskAmantadine
increases risk →

c19early.org

October 2026

Amantadine COVID-19 Randomized Controlled Trials

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Barczyk (DB RCT)−13%1.13 · 0.40–3.23death95 (n)91 (n) Rejdak (DB RCT)66%0.34 · 0.01–8.04death0/491/50 Weis (DB RCT)−67%1.67 · 0.41–6.82hosp.5/1213/121ACT

Late treatment−19%1.19 · 0.53–2.675/2654/26219% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.69

All studies−19%1.19 · 0.53–2.675/2654/26219% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.6900.511.52+

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← Amantadine
reduces riskAmantadine
increases risk →

c19early.org

October 2026

Amantadine COVID-19 RCT mortality results

StudyImprovementRR · 95% CITreatmentControlRelative Risk

Barczyk (DB RCT)−13%1.13 · 0.40–3.2395 (n)91 (n) Rejdak (DB RCT)66%0.34 · 0.01–8.040/491/50

Late treatment0%1.00 · 0.37–2.710/1441/1410% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.99

All studies0%1.00 · 0.37–2.710/1441/1410% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.9900.511.52+

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← Amantadine
reduces riskAmantadine
increases risk →

c19early.org

October 2026

Amantadine COVID-19 peer reviewed studies

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Barczyk (DB RCT)−13%1.13 · 0.40–3.23death95 (n)91 (n) Rejdak (DB RCT)66%0.34 · 0.01–8.04death0/491/50 Weis (DB RCT)−67%1.67 · 0.41–6.82hosp.5/1213/121ACT

Late treatment−19%1.19 · 0.53–2.675/2654/26219% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.69

All studies−19%1.19 · 0.53–2.675/2654/26219% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.6900.511.52+

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← Amantadine
reduces riskAmantadine
increases risk →

c19early.org

October 2026

Amantadine COVID-19 outcomes

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Barczyk (DB RCT)−13%1.13 · 0.40–3.23death95 (n)91 (n) Barczyk (DB RCT)18%0.82 · 0.26–2.55ICU95 (n)91 (n) Rejdak (DB RCT)66%0.34 · 0.01–8.04death0/491/50 Rejdak (DB RCT)39%0.61 · 0.40–0.94no recov.18/4930/50 Rejdak (DB RCT)89%0.11 · 0.01–2.03progression0/494/50 Rejdak (DB RCT)23%0.77 · 0.18–3.24progression3/494/50 Weis (DB RCT)−67%1.67 · 0.41–6.82hosp.5/1213/121ACT Weis (DB RCT)−48%1.48 · 0.95–2.30no recov.37/12125/121ACT

00.511.52+

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← Amantadine
reduces riskAmantadine
increases risk →