In common with most antiviral drugs, remdesivir is more efficacious when administered early in the course of the disease than when administered in the later critical stage [5]. With its broad spectrum of activity, remdesivir inhibits RNA-dependent RNA polymerases and causes arrest in RNA synthesis, most probably by delaying RNA chain termination [6].
Several clinical trials have been conducted to determine the efficacy of remdesivir in COVID-19 patients. Studies have suggested a shortened course of treatment, a reduction in viral load, and clinical efficacy when the drug is administered early in the course of the disease. The significant clinical improvement in respiratory status (68% of 61 patients) and shortening of the disease course was reported in the study by Grein et al. [7]. These results are supported by those of a larger study (n = 1026) by Beigel et al., with the median recovery time being shortened from 15 days with placebo to 10 days with remdesivir, but with no significant reduction in mortality rate [8]. The study conducted by Goldman et al. (n = 397) showed clinical improvement of ≥2 points on a 7-point ordinal scale in 64% and 54% of patients receiving a 5- or 10-day regimen of remdesivir, respectively, with those receiving 10 days of treatment being at a clinically worse status at the beginning of the trial [9]. Remdesivir significantly reduced viral load in a study conducted in China, but the study was terminated early as COVID-19 became controlled during the early stages of the trial and no new patients were available for randomization [10]. Overall, the efficacy of remdesivir in the treatment of COVID-19 is currently questionable as the main purpose of a therapeutic agent during the COVID-19 pandemic is to reduce mortality, not to decrease the length of hospital stay [11].
The adverse effects associated with remdesivir include hypoalbuminemia, constipation, anemia, hypokalemia, increased bilirubin, thrombocytopenia, and acute respiratory failure [9, 10]. The study by Beigel et al. suggested that adverse effects did not differ significantly between placebo and remdesivir [8]. Forty-four clinical trials of remdesivir for COVID-19 are currently registered [12]. Studies with larger populations, and which also compare the efficacy of remdesivir with that of other antiviral drugs, are needed to confirm the relevance of remdesivir in treating COVID-19.