Vol. 57 (2021): Bulletin of the Chemists and Technologists of Bosnia and Herzegovina

Potential drugs for oral treatment of COVID-19

A substantial number of patients with COVID-19, mostly older and those with preexisting chronic diseases need hospitalization, because of clinical progression to severe disease. Therefore, despite several vaccines in use, antiviral therapies that reduce the risk of COVID-19 progression are needed. Oral administration of such therapies would be ideally for the patients, who would easily use it by themselves. So far only one combination of antiviral drugs was approved for emergency use. As reported by manufacturer, combination of nirmatrelvir and low dose of ritonavir is an investigational SARS-CoV-2 protease inhibitor antiviral therapy, for oral administration. Nirmatrelvir is designed to inhibit replication of coronavirus, and low dose of ritonavir, helps maintaining adequate concentration of nirmatrelvir, by slowing down it's metabolism and breakdown. It is not authorized for the pre-exposure or post-exposure prevention of COVID-19 or for treatment in those requiring hospitalization due to severe or critical COVID-19. The U.S. Food and Drug Administration issued an emergency use authorization for this combination, which is different than an approval, in a sense that Agency determined that there is a reasonable believe that this combination can be effective in treatment of mild to moderate COVID-19 in authorized patients (adults and pediatric patients (12 years and older) with positive results of direct SARS-CoV-2 testing and who are at the risk for progression to severe COVID-19, including hospitalization or death), and that potential benefits outweigh the known and potential risks of the product. It is not authorized for use for longer than five consecutive days. So far there are no adequate, approved and available alternatives for the treatment of COVID-19, although some results of the phase 3 of clinical trial published on 16th December 2021, showed that oral molnupiravir (small-molecule ribonucleoside prodrug of n-hydroxycytidine) was found to be effective (significant reduction of hospitalization or death) for the early treatment of COVID-19 (within five days after the onset of signs and symptoms) without evident safety concerns, in the population of nonhospitalized, unvaccinated adults, who were at risk for the progression to severe disease.