PETALING JAYA: A drug normally used for treatment of influenza has garnered a lot of interest since its manufacturer claimed it is also effective against Covid-19.

However, a medical expert has advised caution when prescribing the drug due to lack of definitive information of its efficacy and side effects.

The Health Ministry recently signed a letter of undertaking to purchase the antiviral drug, known as Molnupiravir, as an additional treatment option for Covid-19 patients.

Minister Khairy Jamaluddin said under the deal with manufacturer Merck, Sharp and Dohme, the government would procure a package of 150,000 courses of the medication.

A five-day course of Molnupiravir treatment costs US$700 (about RM2,900).

Universiti Malaya epidemiology and public health professor Dr Sanjay Rampal said initial results of a trial were “promising but not definitive” as it was from only one clinical evaluation.

“More research is needed to get a better estimate of its efficacy and safety,” he told theSun.

Sanjay said typically, a new drug is required to undergo at least two clinical trials up to Phase 3 before being given full registration.

According to American Cancer Society website cancer.org, the safety and effectiveness of a new treatment would be compared with current standard treatments only when the trial reaches the Phase 3 stage.

In the United States, an application to seek approval for a new drug is only submitted to the Food and Drug Administration upon completion of this stage of the trials.

However, an application for emergency use authorisation (EUA), which is a mechanism that allows the use of new drugs in urgent situations, can also be made at an earlier stage of the trial.

Merck has stopped the study early to seek EUA approval for Molnupiravir.

An interim analysis of a trial on 775 participants, who were treated with Molnupiravir, showed that the risk of hospitalisation and death dropped by 50% in at-risk but non-hospitalised patients who had mild-to-moderate Covid-19 infection.

Sanjay said steps should have been taken to compare the efficacy of Molnupiravir with the standard treatment to determine its incremental benefits.

Malaysian Medical Association president Dr Koh Kar Chai said apart from vaccines, an antiviral pill for Covid-19 is important as a medical treatment for infection.

“A huge difference is that we will have treatment available for those who are infected,” he said.

However, he warned that the pill should not be used as an excuse to not get vaccinated.

“Prevention is always better than cure.”

Koh said it is unlikely that people would rush to obtain the drug once it is introduced as they still need a doctor’s prescription for it.

He also stressed that Molnupiravir should not be compared with antibiotics because its usage is specific.