THIS drug manufactured by MSD and Ridgeback Biotherapeutics (referred to as Merck) has been the first oral investigational anti-viral medicine approved by the UK regulatory body MRHA to assist in the fight of mild to moderate COVID-19, with at least one risk factor, in an out-patient setting. Approval of the EUA (emergency use authorisation) is pending for the USA after submission and review of data.

Merck has published that the drug has gone through phase three trials for safety and efficacy, after scoring 11 in WHO outcomes in phase two trials, which gave approval for clinical progression. It has been tried in 170 countries including the hard hit ones such as USA, Brazil, Mexico, UK and now Russia. There are no deaths associated with the usage of molnupiravir according to its manufacturer. The BBC has quoted Merck’s claims to reduce deaths and hospitalisation by 50 per cent in an interim analysis of just under 800 persons. The results published have not been peer reviewed as yet, but the company has indicated willingness and ability to do so based on its confidence in its product.

NHC (ß-D-N-hydroxycytidine), initially developed for influenza, is the active metabolite and it has been around since 1980. In 2003 molnupiravir, the prodrug was introduced. When this oral prodrug is metabolised in the body it is then activated into NHC-TP.

The mechanism of action is to decode the genetic sequence of the viral replication, specifically by altering the viral RNA polymerase enzyme. It has a two-phased attacking mechanism making viral mutations very difficult since the proofreading exonuclease enzymes cannot detect the incorporation of the NHC-TP into the RNA, which is the building block for the virus.

This is a great success story, a light at the end of the tunnel, because of the known contagious nature of the disease and the route of administration, oral rather than the intravenous dosage form. No hospitalisation is required for treatment which means less exposure to the virus, less utilisation of limited and overworked human resources at hospitals and less need for medical supplies including PPE and sometimes oxygen which were in severe shortages in some countries.

The United Kingdom had success in the usage of molnupiravir for the frail and immunosuppressed patients. In the clinical trials treatment commenced early, within the first five days of experiencing the symptoms after testing positive. The recommended regime is twice daily for a period of five to 10 days from 200mg to 800mg, depending on severity.

Two other new oral anti-virals, one by Pfizer (ritonavir) and one by Roche (coded AT-527) are in the queue waiting on approval or authorisation once clinical trials have been deemed satisfactory. It seems that the Pfizer’s pill would be approved in 2022 whilst there has been a delay in about a year due to failure in phase two trials for AT-527. Pfizer’s unique and competitive offer of a tiered pricing plan to prevent prohibition in the roll out in poorer countries might be the game changer the world is waiting on, since it fosters equitable access.

The cost of the treatment is prohibitive. It is estimated at a whopping US$700 per person resulting in more resourced countries like UK, USA, Australia, Singapore and South Korea placing orders in advance. Such high-priced commodity in high demand can lead to drug counterfeiting or look alike in the pharmaceutical industry, so caution in procurement screening is recommended. Initially, a request was made through CARICOM for the Caribbean countries to have some access. Subsequently it was disclosed that pending a WHO approval, CARPHA will be making recommendations for use in the Caribbean since Merck & Co. has recently indicated a more affordable option through its pending licensing agreement with qualified pharmaceutical manufacturers and the United Nations Medicines Patent pool.

Currently, in Guyana, remdesivir is given in the form of IV infusion but requires hospitalisation and monitoring by a doctor. However with the breakdown of trust and the fact that relatives are not at the bedside, care and treatment of patients had become a breathing ground for suspicion, especially when results are not in keeping with expectations. This can undermine all the efforts and sacrifices made by the health care workers especially since PAHO’s protocol does not endorse this particular anti-viral, remdesivir.

It is important though not to dim your judgement with the spotlight on molnupiravir since, as a mutagenic ribonucleoside, some experts in the field expressed concern of undesirable mutation on the host cell and not only on the targeted virus. This caution was raised after animal studies suggested further testing in vivo and monitoring for potential genotoxic effects. If this occurs then unwanted effects like cancer and teratogenicity (birth defects) are some of the concerns to look for later on. Hence, caution is exercised with use in pregnancy and in children. Further, it must be highlighted that in the trials persons on molnupiravir were advised against heterosexual activity so as to prevent pregnancy.

In conclusion, persons should not become complacent or substitute vaccination for treatment since safety concerns may limit usage in the wider population. Emphasis must be placed on disease prevention at all times.
The recommended treatment protocol in the UK for molnupiravir include a positive COVID-19 test with at least one risk factor such as diabetes, obesity, heart disease and old age.

For further pharmacological guidance and physician referral, consult the pharmacist at Medicine Express PHARMACY located at 223 Camp Street, between Lamaha and New Market Streets. If you have any queries, comments or further information on the above topic kindly forward them to medicine.express@gmail.com or send them to 223 Camp Street, N/burg. Tel #225-5142.