Feb 24, 2022


Molnupiravir is a drug initially created to treat influenza, however, it can also treat mild to moderate Covid-19 and those at risk of serious illness.

The much-welcomed antiviral medicine is also expected to work against highly infectious Omicron as other variants of concern and more useful monoclonal antibodies, according to a new study.

It is a small molecule oral antiviral prodrug that is active against severe acute respiratory syndrome SARS-CoV-2. Early treatment with molnupiravir reduced the risk of hospitalization and death in high-risk adults with Covid-19. This drug is a small molecule ribonucleoside prodrug of N-hydroxycytidine that acts against SARS-CoV-2 and other RNA viruses and is a significant barrier to the development of resistance. Helping reduce hospitalization for Covid-19 and community transmission by helping patients clear the infectious virus quickly, is critical. Vaccination is the most important medical intervention available to reduce the risks of hospitalization and death from Covid-19. Molnupiravir is not allowed for use in children and adolescents under 18 years of age. Molnopiravir is not recommended for use during pregnancy because it may harm an unborn baby. Similarly, breast-feeding is not recommended during treatment with molnoperavir and for four days after the final dose. The US Food and Drug Administration (FDA) has granted an emergency use authorization for molnopiravir for use in certain settings where other treatments have not been possible. In a phase 3 trial involving people with Covid-19 at risk of severe disease, molnupiravir was so effective that doctors stopped enrollment early. The advantage of molnupiravir is that, unlike other forms of treatment, it can also be taken out of the clinical setting as an oral tablet. Many people want antiviral treatments that can be taken at home to keep them out of the hospital.

Molnupiravir, like remdesivir, is a nucleoside analogue, this implies that it copies a portion of the building blocks of RNA. In any case, the vehicles work in completely different ways. When SARS-CoV-2 enters the cell, the virus needs to duplicate its RNA genome to form new viruses. Remdesivir is a ‘chain break’. It prevents the enzyme that builds these RNA “chains” from adding more bonds. Molnupiravir, on the other hand, is incorporated into the burgeoning RNA strands, and once inside, chaos occurs. The compound can change its composition, sometimes mimics a cytidine nucleoside and sometimes it mimics uridine. Those strands of RNA become false blueprints for the following round of the viral genome. Wherever a compound is introduced and this harmonic shift occurs, a point mutation occurs, Plimber says. When enough mutations accumulate, virus numbers collapse. “This is what we call killer mutations,” he adds. “The virus basically turns into death.” And because the mutations accumulate randomly, it is difficult for viruses to develop resistance to molnopiravir – another advantage of the compound.

The combination of molnopiravir and nirmatrilvir is essential to enhance antiviral efficacy, reduce toxicity, and avoid drug resistance in patients with COVID-19. Effective antiviral therapy, especially rapid reduction of viral load, is expected to improve patient outcomes but also reduce transmission of the virus. When oral antiviral agents become widely available and affordable, real-world implementation will represent a major innovation in combating the sudden rise in the Omicron variant.