Molnupiravir is used to treat COVID 19. It is sold under the Lagevrio brand name and inhibits RNA virus replication.


Molnupiravir is a type of prodrug. Prodrugs are compounds used to improve the distribution, absorption, excretion and metabolism of drugs. It is used to improve bioavailability when the drug is difficult to absorb in the gastrointestinal tract.  Molnupiravir causes copy errors in the virus during RNA replication.


Molnupiravir was originally developed to treat the flu. It was developed by Emory University’s Drug Innovation Ventures. In the year 2021, the use of Molnupiravir for the treatment of COVID 19 was approved by the UK government.


Molnupiravir prevents the growth of the virus. This is done by increasing the mutations in the virus. After ingestion molnupiravir is first metabolized to ribonucleoside analogs. Nucleotide analogs or Ribonucleoside analogs are used as antiviral components and act as chain breakers. Molnupiravir is metabolized to a ribonucleoside which is called cytidine.

Lethal Mutagenesis

Molnupiravir kills the virus using error catastrophes or lethal mutagenic effects. Molnupiravir comes in two forms. One is cytidine and the other is uridine. When RNA containing molnupiravir is replicated, it may be interpreted as cytidine or uridine. The virus does not recognize uridine and cytidine as errors. This error-reading mechanism is important for viruses. This is because after reading these errors, the virus corrects the mutation into the correct virus.

Understanding of Lethal Mutagenesis

For example, the viral RNA is ABC. However, it is copied as an ADC. That is a mutation. Mutations can be either favorable or unfavorable. Viruses usually identify errors. Here, B is mistakenly copied as D. Then fix such an error. Here, the virus cannot detect the error caused by molnupiravir. Eventually, the mutation level will be so high that the virus will not survive. This is known as lethal mutagenesis.

Usage of Molnupiravir in India

In the month of April 2021, the pharmaceutical company CIPLA was licensed to manufacture, sell and distribute molnupiravir in India.

Molnupiravir Pill

In November 2021, Merck, a privately held pharmaceutical company, announced the development of its first oral molnupiravir antiviral drug. The name of the Molnupiravir tablet is Mjolnir. Patients should take 4 capsules of molnupiravir per day. And during the course of treatment, a total of 40 tablets will be taken.


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