Synonyms: EIDD-2801 | EIDD2801 | Lagevrio® | MK-4482 | MK4482

molnupiravir is an approved drug (UK (2021))

Compound class: Synthetic organic

Comment: Molnupiravir (EIDD-2801, MK-4482) is an oral, broad-spectrum antiviral drug [1,8]. The proposed INN molnupiravir was released by the WHO in a special release to cover COVID-related therapeutics in October 2020 (Proposed INN: List 124-COVID-19). Chemically molnupiravir is the isopropylester prodrug of the ribonucleoside analogue β-D-N⁴-hydroxycytidine (EIDD-1931, or N-hydroxycytidine) [10-11]. Functionally, the active form of molnupiravir is incorporated into the virus' RNA by the viral RNA-dependent RNA polymerase (RdRp) during replication, which results in lethal mutagenesis [4]. Molnupiravir was originally designed by Emory University scientists to inhibit replication of influenza virus. It has subsequently been tested for activity against other RNA viruses, including pandemic SARS-CoV-2, SARS-CoV and MERS-CoV [14]. Molnupiravir was being progressed for COVID-19 in a collaboration between Ridgeback Biotherapeutics and Merck. In vivo therapeutic and prophylactic potential was reported in a peer reviewed manuscript in February 2021 [12].
There is concern that molnupiravir may induce mutations in the host, based on evidence from mammalian cell culture experiments [13] and using the Ames test (bacteria).