How COVID Antiviral Pills Work and Where to Get Them for Free

More than 1,000 US pharmacies began ordering COVID-19 antiviral pills this week as part of the White House's Test to Treat program, which provides the medication free of charge.

President Joe Biden announced the initiative at his State of the Union address last week, referencing Pfizer's Paxlovid, which has been shown to reduce the chances of hospitalization or death due to COVID-19 by nearly 90% and received emergency use authorization from the Food and Drug Administration in December.

The orders must still be shipped but Pfizer is expected to deliver 1 million pills to drugstores by the end of the month and "more than double that" in April, Biden said in his address, adding "We're leaving no one behind or ignoring anyone's needs as we move forward."

Here's what we know about COVID antiviral medications, including how they work and where you can get them.

Who can take COVID antiviral pills?

Paxlovid received emergency use authorization from the Food and Drug Administration in December for use on patients 12 and up who weigh at least 88 pounds.

On Wednesday, Pfizer said it had begun Phase 2 and 3 clinical trials on Paxlovid in children ages 6 to 17, with the hope of receiving approval to use the treatment on patients under age 12.

The White House hasn't announced full details for the Test to Treat program, White House Coronavirus Response Coordinator Jeff Zients said last week, but testing and treatment would be available to individuals for free "all in one stop."

It's not clear if patients would be asked to show proof of insurance.

Previously, some health care providers were unsure about fulfilling prescriptions for the antivirals, and supplies were extremely limited.

"The demand is just outstripping the supply for these oral antivirals right now due to the quickly spreading omicron variant," Dr. Elise Choi, an internist in Somerville, Massachusetts, told the AMA in early February. "Most of the access for these medications are being directed by the state health departments to specific local health departments, pharmacies, clinics, hospitals and physician offices."

Choi added that not all doctors could get antivirals on-demand for their patients. "There's a lot of state-to-state variability."

Which pills will be made available?

In his address, Biden indicated Pfizer's Paxlovid has been authorized as part of the Test to Treat program.

The oral medication has proven 89% effective in preventing hospitalization and death from COVID-19 if administered within three days of symptoms, according to the pharmaceutical giant. If given within five days, it still reduced the risk of severe reaction by 88%.

Merck's antiviral, molnupiravir, also received emergency authorization from the FDA in November. The White House already purchased 1.7 million courses of the drug in anticipation of that approval, but Biden did not mention it in his remarks.

Molnupiravir, developed by Merck and Ridgeback Biotherapeutics, has ultimately proven much less effective than Paxlovid. (It was only narrowly approved by the FDA's advisory committee by 13 to 10.)

In clinical trials, it only decreased the risk of hospitalization from COVID-19 by 30%, down from 50% in early results.

"That's not all that good. It's pretty lackluster," Katherine Seley-Radtke, a University of Maryland medicinal chemist, told Nature.

How do antiviral pills work?

Several vaccines have proven effective at preventing COVID-19 and lessening the severity of disease for breakthrough cases.But for those already infected, antiviral drugs are needed to actively treat the condition.

Paxlovid is actually a combination of two medications: the existing antiviral ritonavir paired with the newer nirmatrelvir.

Nirmatrelvir is designed to block the activity of the SARS-CoV-2-3CL protease, an enzyme that the coronavirus needs to replicate. The ritonavir allows the medication to remain active in the body longer and at higher concentrations.

The two work together, disrupting the replication of COVID-19 virus in infected patients. Pfizer says the pill has proven effective against more serious delta and the omicron variants of COVID-19.

The Paxlovid protocol requires taking two nirmatrelvir tablets and one ritonavir tablet twice daily for five days -- within five days of symptoms appearing. Reported side effects during trials were similar to those of a placebo, according to Pfizer.

Molnupiravir's structure actually resembles the chemical-building blocks) used to make COVID's RNA: The drug "sneaks" into the virus' RNA as it's being synthesized and mutates it to the point that the viral proteins it creates can no longer function.

Possible side effects of molnupiravir include diarrhea, dizziness, and nausea, according to Yale Medicine.

Where can I get antiviral pills?

CVS, Walgreens and Kroger are among the "hundreds of sites" that are offering the medication, a White House official told Axios. Orders have already been submitted this week.

Someone will have to prescribe the medications, though, so any pharmacy you go to will need to have a clinic, like CVS' MinuteClinic, where clinicians can screen, diagnose and prescribe.

A representative for CVS told CNET the chain's large number of branches make it "uniquely positioned to help support the government's Test to Treat initiative."

The medications will also be distributed directly to medical clinics, community health centers, long-term care facilities and veteran health centers, Zients said Wednesday.

When will the medications be available?

The White House worked with Pfizer to speed up delivery of the pills, making hundreds of thousands of them available much earlier than expected. Paxlovid is now available to anyone who tests positive for COVID-19, but the availability of the drug varies greatly across the country.

CVS, which has 1,100 HealthHUBs and MinuteClinics nationwide, "look[s] forward to helping provide expanded access as additional inventory becomes available," a spokesperson told CNET.

A Walgreens spokesperson said the company "will provide additional details regarding rollout in our stores as it becomes available."

If the rollout follows the precedent of the distribution of free N95 masks, some stores and regions will have access before others.

GoodRX has a tracker showing where Paxlovid and molnupiravir are available.

Could widespread use of antivirals lead to drug-resistant COVID?

The overuse of some antibiotics has led to drug-resistant strains of diseases like tuberculosis and gonorrhea. But that's unlikely to happen with Paxlovid because the course of treatment is so short -- just five days.

"It won't put selective pressure on the virus to evolve," Monica Gandhi, an infectious disease expert at the University of California, San Francisco, told CNET earlier.

Will making the pills available cause vaccination rates to decline?

"During this pandemic, we've done everything in our power to get people to take the vaccine -- we've incentivized, cajoled, mandated," Gandhi said."At this point, a year since the first vaccine was announced, I don't think we're going to change someone's mind."

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.