Repurposed Drugs during the Outbreak of Pandemic COVID-19: A Mini-Review on Their Molecular Structures and Hit-and-Trial Results

One of the most significant threats to global public health in the 21st century is the novel coronavirus disease (COVID-19) caused by SARS-CoV-2. It rapidly turned into a global pandemic after it was identified in late 2019, and the World Health Organization announced the end of the pandemic on May 5, 2023. Current strategies for managing this disease include vaccination and repurposing antimalarial and antibiotic medications to alleviate symptoms like fever and throat pain, which are associated with acute respiratory distress syndrome (ARDS). Antiviral drugs such as chloroquine, hydroxychloroquine, azithromycin, remdesivir, and favipiravir have been repurposed for the treatment of COVID-19. They were previously recommended for treating SARS-CoV and MERS-CoV. However, the inefficacy and adverse side effects of these repurposed drugs led to a decrease in their widespread use in treating COVID-19 patients. The lack of approved drugs for combating this coronavirus and its unpredictable variants remains a significant challenge.