What is Paxlovid and how will it help fight coronavirus? | Health
The Biden administration announced on April 26, 2022, its intention to increase the availability of the COVID-19 drug Paxlovid, pledging to put more treatment pills in the hands of Americans. An oral antiviral, Paxlovid has been shown to reduce the risk of hospitalization in people with COVID-19, but has suffered from slow rollout in pharmacies across the United States. (Also read: The gap between the second dose of Covid vaccine, the precautionary vaccine must continue to be 9 months)
Patrick Jackson, an infectious disease physician and scientist at the University of Virginia, has helped treat hundreds of COVID-19 patients and participated in Paxlovid clinical trials. The Conversation asked him to explain what the drug does and what impact wider availability could have in the fight against coronavirus.
What is Paxlovid and how does it work?
Paxlovid is made up of two protease inhibitors, one of which is used in the treatment of HIV as a booster medication. Protease inhibitors are synthetic drugs that block enzymes that viruses need to replicate. Paxlovid’s combination essentially prevents the coronavirus from completing its life cycle.
If not interrupted, SARS-Cov-2 would normally create the proteins it needs by making a polyprotein or long chains of amino acids. Then protease, a viral enzyme, activates the polyprotein chains by cutting them into smaller parts. Paxlovid blocks the protease from doing this, thus preventing the virus from becoming active.
How much of a game changer could this be in the fight against COVID-19?
It’s a bit limited. It could be beneficial for people at high risk of serious illness and possibly death, such as the elderly or those with high blood pressure, diabetes, obesity, heart disease, or immunosuppression. And it’s the people we’re most worried about when it comes to COVID-19.
But the more medically complicated a person is – by which I mean the more health conditions and medications they take – the more likely Paxlovid is to interact with one of their medications. This means that one medicine can alter or interfere with the way another medicine works, which can be dangerous.
Some of the really important Paxlovid interactions are with anti-rejection drugs for people who have transplants. Many blood thinners have interactions with this drug that can be very serious. Medicines that treat abnormal heart rhythms can be a major problem if patients taking these medicines are taking Paxlovid. And there’s a whole range of other things that it doesn’t mix well with in the body.
Some of those who could benefit the most from Paxlovid are also most at risk for drug interactions with Paxlovid. That makes it a little less useful.
And Paxlovid has only been studied in unvaccinated patients. So it’s not clear how well it will work in a vaccinated population – that is, we don’t know what additional benefit it provides on top of vaccination. I think it would work, but we don’t know how much. And I wonder how much of a game changer it is when we can just vaccinate more people and probably get more population-level benefits.
Is Paxlovid accessible to everyone?
It is a prescription drug, so you should talk to your doctor about it. You must have symptoms of COVID-19 and test positive for the virus – not necessarily with a PCR test; it can be with a home test. But you really need to have a diagnosis.
And this drug has an Emergency Use Authorization from the Food and Drug Administration, which has more restrictions than just having full FDA approval. Pharmacies are responsible for ensuring that the prescribed use is appropriate for this medication.
So many pharmacies will require information from the doctors who prescribe them – things like documentation of symptoms. So, depending on the pharmacy, Paxlovid may be a bit trickier to get.
The #1 problem will likely be doctors’ reluctance to prescribe it. I think part of it comes down to a lack of awareness, and part of it is a result of the complexity of making sure you’re using it appropriately and not hurting your patient through drug interactions.
I will definitely prescribe it to my patients when appropriate. But I have to go through their entire list of medications and check for drug interactions and recheck myself with another resource.
Why was there a problem in the delivery of the drug to pharmacies?
Initially, I think the manufacturer and distributors were trying to kind of spread it. Doctors and patients therefore needed to determine which pharmacies had the drug available and contact them quickly to obtain Paxlovid. But pharmacies would run out even if they could have been listed on a website as having received a supply.
But that becomes less of a concern, now that there is more supply of drugs.
What did the White House say it would do to speed things up?
The government is buying more drugs and distributing them to more pharmacies, which has helped to some extent. And the Biden administration has been making some noise to try to make the drug more readily available at test sites and clinics to treat — something that has so far been difficult.
By Patrick Jackson, Assistant Professor of Infectious Diseases, University of Virginia