Even before the US president tested positive for Covid-19, Dr David Smith – an infectious disease consultant at the University of California, San Diego – said he was getting calls daily from other physicians seeking advice on whether to prescribe Paxlovid, an antiviral drug, to patients with coronavirus.
The calls come from “doctors who haven’t educated themselves on how to use the drug, and so they are a little skittish about it”, Smith said. “If I had a magic wand out there … one of the things that I would want to do is to get more people comfortable with the medication.”
The past month has seen increased scrutiny of the potential benefits and drawbacks of Paxlovid after Joe Biden and his top medical adviser, Dr Anthony Fauci, received the drug to treat their Covid-19 cases.
Infectious disease experts say the dearth of knowledge about the drug – some of it simply because it’s new – and misconceptions about its usefulness have limited its ability to keep patients from becoming more sick from the virus.
“I think some clinicians have unfortunately written off Paxlovid as not a good option for patients who would very much benefit from it based on what is a misperception that it doesn’t work or doesn’t do a good job,” said Jennifer Nuzzo, an epidemiologist and director of the Pandemic Center at Brown University School of Public Health. “I just worry that we are robbing people of an important tool.”
Paxlovid, which Pfizer developed and the Food and Drug Administration approved late last year, is a combination of two antiviral medications that “interfere with the multiplication of the virus”, said William Schaffner, an infectious disease expert at Vanderbilt University School of Medicine.
That prevents the virus from causing more damage, Schaffner explained. The drug reduced the need for hospitalization for people with Covid-19 by 88% as compared with patients who were given a placebo during a clinical trial, according to the FDA.
Paxlovid is meant for patients who are at the greatest risk of developing serious disease from the virus, such as older adults with underlying illnesses including diabetes, heart and lung diseases, and people who are immunocompromised, Schaffner said.
“The risk factors are quite broad for eligibility for this drug: being heavy, being older,” Smith said. “A few comorbidities, like high blood pressure, diabetes, really does put somebody at higher risk and thus qualifies them for this drug.”
Despite its potential benefits, the drug has been underused and left on shelves to possibly expire, according to government data and reports from physicians in the US and elsewhere.
That’s in part because of the limited time in which the drug can be helpful, according to infectious disease experts.
To be effective, the drug must be taken within five days of the onset of symptoms. But people may not test themselves right away when they have a sore throat or initially take a home test that provides a negative test result, before they take a second one a day later that shows they are positive, Andrew Pekosz, a Johns Hopkins virologist, explained.
And many people don’t have a primary care physician or an easy way to an urgent care center to get a prescription, Nuzzo said.
“The clock starts ticking away such that you may miss your window of opportunity to start the treatment,” Nuzzo said.
To make it easier for patients to obtain the drug, this month, the FDA authorized pharmacists to prescribe it to Covid patients.
But another big concern among providers and patients is a possible rebound of Covid-19 symptoms after Paxlovid treatment. That’s what happened to Fauci, who’s been the top presidential medical adviser throughout the pandemic. He told news organizations his symptoms from the rebound were worse than before the treatment but improved after a second course of Paxlovid.
“The biggest question that’s on people’s minds is whether they will experience a rebound infection,” Nuzzo said. “The calculus is very clear for people who are at high risk of severe illness because that seems like a minor inconvenience compared to the possibility of going to the hospital. But for people who are not at high risk, I think there’s been a question of whether they would truly benefit from [Paxlovid], given that we don’t know quite how well it performs in people who are both vaccinated and not high risk.”
Paxlovid, like other medications, also has potential side effects – patients have reported a metallic taste and diarrhea. Doctors must also consider its interaction with other drugs.
“It’s not the easiest drug to prescribe,” said Pekosz. “There are a lot of pre-existing conditions where Paxlovid might be tricky to be prescribed for because it does have some side effects.”
To help get the most benefit from this new tool, infectious disease experts recommended that people immediately contact their doctor if they contract Covid.
They also called for more education for doctors. Smith recommended that doctors review the National Institutes of Health treatment guidelines and participate in continuing medical education forums about the drug.
Another question on the public’s mind regarding Paxlovid is the potential implications it presents for Biden’s health.
The Paxlovid study “really did reduce the risk of hospitalization and death enormously”, Smith said. “So I think he’s in good hands with what’s going on and how he’s being treated, so hopefully it is only a bump in the road.”