Pills for COVID-19? Here are the latest medicines created to blunt the effects of the pandemic

Dubai: After nearly two years since the coronavirus pandemic took hold, the world may soon have access to oral pills to beat the infection, at least according to two leading pharmaceutical companies in the world.

Even as nations scramble to control the spread of the pandemic and rush to reach ideal vaccination rates, Merck & Co Inc. got regulatory approval for its COVID-19 pill Molnupiravir in the UK.

Soon after, on November 5, Pfizer also announced that their experimental antiviral pill (brand name Paxlovid) to treat COVID-19 cut the chance of hospitalisation or death by 89 per cent for adults at risk of severe disease.

Pfizer’s reported results were much higher than those reported for Merck’s molnupiravir pill, which shows a 50 per cent cut in hospitalisations and risk of death. Reuters reported that Pfizer said it expects to submit interim trial results for its pill to the US Food and Drug Administration (FDA) before the national Thanksgiving holiday on November 25.

Merck’s pill is still under review in the US and Europe. However, Bangladesh will be the first country to start selling a cheap and generic version of Merck's antiviral pill, local Beximco Pharmaceuticals said, Reuters reported. Merck has also signed deals to sell around 6 million courses of the pill to various governments.

Why is this big?

Currently all COVID-19 treatments require an IV or injection. Since both of these methods require hospitalisation in many cases, researchers worldwide have been racing to find a pill to treat COVID-19.

The ease of a pill is that a course can be taken at home to ease symptoms, speed recovery and keep people out of the hospital. Nearly 80 per cent of COVID-positive individuals don’t require hospitalisation and getting the pills prescribed could further reduce the need to go to a hospital.

Pfizer’s results of nearly 90 per cent of a cut in hospitalisation and risk is additionally promising since the study was done on adults who were unvaccinated and considered high risk for hospitalisation due to health problems like obesity, diabetes or heart disease.

How do the pills work?

Both pills work by restricting the virus’s ability to replicate inside the body. The Merck drug works by interfering with the coronavirus’ genetic code. Molnupiravir disrupts the replication of the virus.

It mimics a building block of the virus's genetic material, and so when the virus reproduces, gets incorporated into its RNA. This creates errors in its genetic code, and when enough of these errors build up, an "error catastrophe" stops the virus reproducing altogether.

This destructive process inspired researchers to name the drug after Mjolnir, the hammer wielded by the god of thunder Thor.

Paxlovid by Pfizer also stops viral replication in a different way. This is a more traditional method wherein the pills works by binding to an enzyme - called a protease - to stop it from functioning. This process has been successfully used in various antiviral treatments including the ones for HIV and hepatitis C.

The coronavirus needs protease to be functional in order to reproduce.

How soon should the course be taken

Since these medicines work by restricting the virus’s ability to reproduce, it is imperative to start the course in the first few days of testing positive and/or showing symptoms. Molnupiravir, for example, should be taken as soon as possible following testing positive (and within five days of symptoms starting). The course is for five days.

The Pfizer drug reportedly appears to be beneficial when administered within three to five days of symptom onset.

The earlier, the better

The one con of these medicines is that it could be too late to work if the pills are administered by the time someone has deteriorated and has been raced to hospital gasping for oxygen. The pills work by controlling replication and on waiting too long, it is highly probably that virus may have spread far enough to cause serious damage.

The ability to get prescriptions for this medicine soon after a positive COVID-19 test or within a couple of days of the onset of symptoms is crucial and could mean a serious reduction in risk of hospitalisation, death or serious post-COVID effects.

- Inputs from agencies