Molnupiravir, Merck’s new antiviral drug, was recently tested against a placebo in people at high risk of developing severe Covid disease. Of the 377 people who got the placebo, 14.1%, (53 patients in total), were hospitalized with 8 dying. Only 7.3% (28), of the 385 patients who got the drug were hospitalized in the same time period. More importantly, none of the patients who got the drug died. There were no significant side effects from the drug. It’s a relatively small trial, but some impressive results nonetheless.
The drug works by mimicking building blocks of the coronavirus’s genetic material, RNA. The fake building blocks interfere with the enzyme the coronavirus uses to copy its RNA. Although similar to Remdesivir, the previously known antiviral drug, this one works a bit differently. Remdesivir is a delayed stop sign. When it is inserted into a growing strand of RNA, it slows the RNA replicating enzyme, eventually causing it to stop the process. Molnupiravir instead pockmarks the RNA with many mutations. Those mutation potholes don’t just stop the RNA-copying enzyme, they also cause damage to other proteins the virus needs to infect cells and replicate.
Viruses can develop resistance to some antivirals. This has happened already with the anti-influenza drug osteltamavir (Tamiflu). But with molnupiravir, resistance mutations can’t emerge because the drug makes too many other damaging mutations.
The regimen is familiar to anyone who has taken Tamiflu for the seasonal flu. Patients will take 4 capsules twice a day for five days. Pfizer is developing a similar pill, as are the companies Atea Pharmaceuticals and Roche. They are unlikely to be available for use until next year.
There are issues, however. If you don’t take it relatively early during an infection before too much virus replicates, it won’t work well, just like Tamiflu. Literally, it must be taken within days of symptom onset. Before the pandemic, with the flu, an assumption could be made that you have it based on symptoms and Tamiflu can be prescribed, but the flu and Covid share almost the exact same symptoms. Tamiflu will not work for Covid, and molinupiravir won’t work for the flu. The bottom line is that if you are concerned, have had significant exposures and/or have health risk factors, see a healthcare provider and GET TESTED for Covid.
There is always an argument about equity when it comes to any medical management. We certainly see this when it comes to the vaccine with the lionshare of the vaccine being used in wealthier countries. The same goes for healthcare management in this country. Sadly, we have the most out of proportionally expensive healthcare system and if you do not have insurance, things can be really challenging. It’s challenging enough even if you do have insurance. The same will go for this medication. A course of molnupiravir is $700. The monoclonal antibodies are triple that.
Once again, we have effective treatment options but the best strategy against Covid is one that prevents you from getting it in the first place, getting it again, but more importantly, not spreading it to others. And the vaccine is still the most effective strategy in managing this pandemic. And it’s FREE! And safe. And effective. What’s the problem? Stubbornness? Politics? Ego?
Recent headlines have announced how the numbers are on the decline. That’s great news but we have just surpassed over 700,000 deaths overall in the US and continue to have ~2000 deaths a day. We also need to remember that we had a dip in numbers last spring, only to have a resurgence soon afterwards and the pandemic continues to rage in other parts of the world. We are entering the traditional seasons when viral infections spread more readily in an environment in which we continue to have all of our kids under 12 being unprotected, as well as most kids above 12, along with a good proportion of adults continuing to be unvaccinated. People just don’t get it. Although vaccination is clearly a good idea to protect individual health, it is more about the health of our society. This is a public health problem.
Stay safe and be well.
AC