What Are the Side Effects of Paxlovid?

Millions of Americans have turned to the prescription pill Paxlovid to help keep a case of COVID-19 from progressing to a severe infection. And researchers say the oral antiviral has saved thousands of lives — as many as 1,500 each week in the U.S., according to a March estimate from the Food and Drug Administration (FDA).   

While doctors say Paxlovid is well-tolerated by patients, some people can experience side effects when taking it, as is the case with any medication. The most common side effects of Paxlovid include an impaired sense of taste (often a metallic taste) and diarrhea, the FDA reports. People can also experience muscle aches or nausea when taking Paxlovid, says Bruce Farber, M.D., chief of public health and epidemiology at Northwell Health in New Hyde Park, New York.

“But these [side effects] don’t affect everyone,” Farber says. “There’s probably a very large percentage of people who have no trouble taking it.”

Plus, when you stop taking the medication, which is a five-day course, the side effects subside. And keep in mind that many of these symptoms — change in taste, stomach upset and muscle aches — are among the ones you might see when fighting a case of COVID-19 anyway, says Nicholas A. Turner, M.D., an infectious disease specialist at Duke Health.

The difference is, when you’re taking Paxlovid, you’re significantly less likely to experience some of the more serious symptoms of COVID-19 that could put you in the hospital, such as difficulty breathing. “It can really make a dramatic difference, and certainly you’d rather have a metallic taste in your mouth than be sick in the hospital,” Farber says.

Does Paxlovid interact with other medications?

Where you run into the risk of experiencing more side effects, and potentially serious ones, is if you’re already taking a medication that interacts with Paxlovid — and several do, including common blood pressure and blood-thinning medications. (See the full list on this FDA fact sheet.)

A big reason: Paxlovid, which stops the coronavirus from replicating in the body’s cells, can slow down the way your body gets rid of other medicines, Turner says. “If you cannot clear out another medicine as fast as the body might normally do, you could effectively get an overdose on one of your other medications,” he says.

The key, says Camille Kotton, M.D., clinical director for transplant and immunocompromised host infectious diseases at Massachusetts General Hospital in Boston, is to make sure your health care provider is aware of all the medications you take. “They should carefully review them for potential, even severe, drug interactions,” she says.

If you are taking a medication that interacts with Paxlovid, that doesn’t preclude you from getting the treatment. Your doctor may be able to adjust the dosage of that drug while you’re taking the treatment, or have you temporarily stop it, Turner says.

There are also other antiviral treatments for COVID infections that can be considered, too, including remdesivir, which is administered by IV, and the antiviral pill molnupiravir (Lagevrio), which health officials say can be used if the other two therapies are not good options.