Molnupiravir, developed by the US drug companies Merck, Sharp and Dohme (MSD) and Ridgeback Biotherapeutics, is the first antiviral medication for Covid which can be taken as a pill rather than injected or given intravenously. It has been authorised for use in people who have mild to moderate COVID-19 and at least one risk factor for developing severe illness. Such risk factors include obesity, older age (>60 years), diabetes mellitus, or heart disease. Countries like USA, UK, Singapore, Australia, South Korea etc. has already approved this medicine for oral uses. In Bangladesh, Renowned pharmaceuticals such as Eskayef, Beximco has gotten DGDA's emergency production and marketing authorization of this pill and already started distributing.
Structure & Chemistry
Molnupiravir is a prodrug of the synthetic nucleoside derivative N4-hydroxycytidine (also called EIDD-1931), and exerts its antiviral action through introduction of copying errors during viral RNA replication. In order to synthesize molnupiravir, in the first step, acetone is used as a protecting group to render two of the three hydroxy groups of uridine unreactive to treatment with the acid anhydride of isobutyric acid, which converts the third hydroxy group to its ester. Treatment with 1,2,4-triazole and phosphoryl chloride produces a reactive intermediate in which the triazole portion can be replaced with hydroxylamine. Finally, removal of the protecting group using formic acid converts the material to molnupiravir.
How does Molnupiravir Work?
Molnupiravir works by disrupting the virus's reproduction. Once the virus gets inside the body's cells, it replicates its genome, which is made not of RNA (ribonucleic acid). These replicated genomes are then formed into complete virus particles which burst out of the cell and continue to spread around the body. The molecules of molnupiravir are absorbed by virus-infected cells, where they are converted into a defective version of the building blocks of RNA. So, when the virus tries to replicate, the resulting virus particles have defective genetic material and can no longer reproduce. This means that the viral load should remain low, which reduces the risk of serious disease. Since molnupiravir targets the RNA that SARS-CoV-2 uses as its building blocks, it should be equally effective against all coronavirus variants.
How effective is Molnupiravir?
In clinical trials, it was found to be effective in reducing the risk of hospitalisation or death for at-risk non-hospitalised adults with mild-to-moderate COVID-19 by 50 per cent which is surely groundbreaking. In another clinical trial of molnupiravir on 775 patients who had recently caught Covid found: 7.3% of those given the drug were hospitalised that compares with 14.1% of patients who were given a placebo or dummy pill there were no deaths in the molnupiravir group, but eight patients who were given a placebo in the trial later died of Covid.
Cost effectiveness of this treatment?
Eskayef Pharmaceuticals has started selling this drug labeled as 'Monuvir' which costs tk 50 is now available in all drug stores and hospitals all over the country. Patients will take four capsules twice a day for five days, so the full course would cost Tk 2,000 approximately.
Does Molnupiravir has any Side Effects?
Based on the data in the company’s release, the drug appears to have a clean safety profile, meaning there were no serious side effects in trial volunteers. Although there could be a chance of birth defect.