Add-on amantadine of no help in hospitalized COVID-19 patients

The addition of amantadine to standard care falls short of improving the likelihood of recovery of patients hospitalized with COVID-19, according to a study.

The multicentre study included patients with oxygen saturation ≤94 percent and who did not require high-flow oxygen or ventilatory support. These patients were randomly assigned to receive oral amantadine or placebo for 10 days in addition to standard care. The primary endpoint was time to recovery over 28 days since randomization, defined as discharge from hospital or no need for supplemental oxygen.

The study was terminated early due to a lack of efficacy after an interim analysis. Final data comprised 95 patients who received amantadine (mean age 60.2 years, 65 percent male, 66 percent with comorbidities) and 91 patients who received placebo (mean age 55.8 years, 60 percent male, 68 percent with comorbidities).

Median time to recovery was 10 days both in the amantadine and placebo arms (subhazard ratio, 0.94, 95 percent confidence interval [CI], 0.7–1.3). The percentage of deaths and percentage of patients who required intensive care at 14 and 28 days did not significantly differ between the amantadine and placebo groups.

Serious adverse events occurred in 23 patients in the amantadine arm and in 29 patients in the placebo arm, with most deemed unlikely related to treatment. Of the four serious adverse events likely related to treatment, two were cardiac disorders (one in each study arm), one was psychiatric disorder in the amantadine arm, and one was gastrointestinal disorder in the placebo arm. Most of the deaths were caused by COVID-19 deterioration.