Abstract
BACKGROUND: Antiviral drugs have become crucial in managing COVID-19, reducing complications and mortality. Remdesivir has emerged as an effective therapeutic drug for hospitalized patients at risk of disease progression, especially when alternative treatments are infeasible. While the recommended treatment duration of remdesivir extends up to 7 days post-symptom onset, this study examines how early remdesivir administration impacts clinical outcomes. METHODS: We conducted a retrospective analysis using clinical data from consecutively PCR confirmed SARS-CoV‑2 adult patients (≥ 18 years) who received remdesivir during their hospitalization at the department of infectious diseases, Klinik Favoriten in Vienna. The data covered the period from July 1, 2021, to April 31, 2022. Patients were divided into two groups based on the timing of remdesivir administration: an early group (0-3 days since symptom onset) and a late group (≥ 4 days since symptom onset). The primary outcome was in-hospital disease progression, assessed using the WHO COVID-19 Clinical Progression Scale (≥ 1 point increase). Multivariable logistic regression, adjusted for age, sex, SARS-CoV‑2 variant, and COVID-19 vaccination status, was used to assess clinical outcomes. RESULTS: In total 219 patients were included of whom 148 (67.6%) were in the early group and 71 (32.4%) were in the late group. The average age was 66.5 (SD: 18.0) years, 68.9% of the patients were vaccinated, and 72.6% had the Omicron virus variant. Late remdesivir administration was associated with a significantly higher probability of needing high-flow oxygen therapy (OR 2.52, 95% CI 1.40-4.52, p = 0.002) and ICU admission (OR 4.34, 95% CI 1.38-13.67, p = 0.012) after adjusting for confounders. In the late group there was a trend towards a higher risk of clinical worsening (OR 2.13, 95% CI 0.98-4.64, p = 0.056) and need for any oxygen therapy (OR 1.85, 95% CI 0.94-3.64, p = 0.074). CONCLUSION: Compared to patients who received remdesivir within the first 3 days after symptom onset, administering remdesivir after day 3 in hospitalized COVID-19 patients is associated with higher risk for complications, such as the need for high-flow oxygen therapy and ICU admission.