Xocova vs. Paxlovid: 6 Ways These COVID-19 Medications Compare

COVID-19 is a contagious, viral infection. Since its appearance, scientists have found ways to fight it. Paxlovid (nirmatrelvir / ritonavir) marked a major milestone. It was the first oral medication FDA approved to treat COVID. Xocova (ensitrelvir) is the first oral medication approved to prevent infection after an exposure.

Since Xocova and Paxlovid are both COVID pills, it can be easy to confuse them. But the two have several differences to keep in mind.

Xocova vs. Paxlovid at a glance

The table below highlights the key similarities and differences to consider when comparing Xocova versus Paxlovid.

*Paxlovid is also FDA authorized to treat mild-to-moderate COVID in adolescents ages 12 to 17 who weigh at least 88 lbs (40 kg) and are at high risk for developing severe symptoms.

Below are more details on six ways that Xocova and Paxlovid compare.

1. Xocova is for COVID prevention, and Paxlovid is for COVID treatment

The biggest difference between Xocova and Paxlovid is their approved uses. Xocova is for preventing COVID, and Paxlovid is for treating it.

Xocova is FDA approved to prevent infection if you were recently exposed to someone sick with COVID. It can be prescribed for people ages 12 and older. And it seems to work similarly well for people regardless of their risk for developing severe symptoms.

Paxlovid is approved for adults with mild-to-moderate COVID who are at a high risk for developing severe symptoms. It’s also FDA authorized for mild-to-moderate COVID in children ages 12 to 17 who weigh at least 88 lbs and have a high risk of severe infection. Examples of high-risk groups include older adults and people with weakened immune systems.

Paxlovid’s benefits are most notable for people in this high-risk group. It doesn’t seem to work as well for people with a lower risk of developing severe COVID.

2. Xocova and Paxlovid work in similar ways

Xocova and Paxlovid belong to the same class of medications: protease inhibitors. They work by blocking a protein that the virus that causes COVID needs to multiply. But Xocova works earlier than Paxlovid.

Xocova works before you experience symptoms. It stops the virus from making copies of itself. But it does this before your immune system causes symptoms such as a sore throat and fever. Stopping the virus from making copies this early helps your immune system kill the virus before you feel sick.

Paxlovid works after your immune system has started causing symptoms. At this point, the virus has had enough time to make many copies. Paxlovid’s nirmatrelvir component stops the virus from making more copies. This gives your immune system time to catch up and kill the virus in your body. Paxlovid’s ritonavir component helps the nirmatrelvir stay in your body at higher levels for longer.

Keep in mind that both medications work best if you start them as quickly as possible. So don’t delay an appointment if you’ve been exposed to COVID or develop symptoms of the infection.

Good to know: Paxlovid was studied for preventing COVID, but clinical trials found that it wasn’t effective for this use. Xocova has been found effective for COVID treatment. But its success in preventing infection (which is unique for its class) led researchers to seek approval for that use.

3. The way you take Xocova and Paxlovid is different

Xocova and Paxlovid also have different dosages.

Xocova is a once-daily medication. It comes as a 125 mg tablet. On Day 1, you should take 3 tablets by mouth one time. On Days 2 through 5, take 1 tablet by mouth once a day. Xocova works best if you start taking it within 72 hours (3 days) after being exposed to someone who’s sick with COVID.

Paxlovid comes with two different tablets that you’ll need to take together: nirmatrelvir 150 mg tablets and ritonavir 100 mg tablets. It’s recommended to start Paxlovid within 5 days of when you first develop symptoms. But the sooner you start taking it, the better.

Paxlovid’s recommended dosage depends on your kidney function. Your prescriber will need to check your kidney health before you start taking Paxlovid. So you may need to go for blood tests before they can prescribe it for you.

The table below highlights the recommended Paxlovid dosages, separated by estimated glomerular filtration rate (eGFR, a marker of kidney function). Don’t try to adjust your dosage on your own. Your prescriber will know which dosage schedule is appropriate for you.

4. Paxlovid is considered safe during pregnancy

Pregnancy makes you more likely to develop severe COVID. The infection can also be harmful to a fetus. If you get sick with COVID while pregnant, your prescriber may recommend taking Paxlovid. Studies suggest that the medication is likely safe during pregnancy. And the American College of Obstetricians & Gynecologists recommends Paxlovid as the preferred treatment for mild-to-moderate COVID during pregnancy.

If you’re pregnant, you should avoid Xocova. Animal studies suggest that it may be harmful to a developing fetus. Because of this, your healthcare team may ask you to take a pregnancy test before they prescribe Xocova. The manufacturer also recommends using an effective birth control method while taking Xocova and for at least 2 weeks after your last dose.

5. Xocova and Paxlovid have different side effects

Xocova and Paxlovid have different side effects, but both are well tolerated.

Common Xocova side effects include:

• Headache

• Diarrhea

• Cough

As mentioned, Xocova may cause harm to a fetus if taken while pregnant. There’s also a risk of allergic reactions, but this is very rare.

Common Paxlovid side effects include:

• Taste changes (sometimes called “Paxlovid mouth”)

• Diarrhea

Less commonly, people have also reported headaches and a temporary rise in blood pressure while taking Paxlovid. And allergic reactions are rare but possible. There’s also a theoretical risk of liver damage from the ritonavir in the medication. This hasn’t been seen in people taking Paxlovid. But to be safe, you shouldn’t take Paxlovid if you have severe liver problems.

6. Xocova and Paxlovid have similar interactions

Drug interactions are another thing to consider if you’re taking Xocova or Paxlovid. Each medication interacts with several medications. Many of the interactions are the same for Xocova and Paxlovid. These include:

• Quinidine

• Apalutamide (Erleada)

• Enzalutamide (Xtandi)

• Carbamazepine (Tegretol)

• Phenytoin (Dilantin)

• Colchicine (Colcrys, Lodoco, Mitigare)

• Rifampin (Rifadin)

• Lurasidone (Latuda)

• Ergot migraine medications, such as ergotamine

• St. John’s wort

• Simvastatin (Zocor, FloLipid)

• Finerenone (Kerendia)

• Triazolam (Halcion)

In some cases, you may not be able to combine certain medications with Xocova or Paxlovid. Keep in mind that this isn’t a full list of all the medications and substances that interact with Xocova or Paxlovid. So be sure to share a medication list with your prescriber and pharmacist before taking either.

Can you take Paxlovid if you’ve recently taken Xocova?

Yes, you can take Paxlovid if you recently took Xocova. They don’t interact with each other. And while Xocova can lower the risk of COVID infection, it doesn’t eliminate it. So you could still get sick even if you take Xocova as instructed. And if you do, you may qualify for Paxlovid.

If you develop COVID while taking Xocova, ask your prescriber if you should finish your course. There are no standard instructions about whether you should continue it if you get sick while taking it.

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Written by:

Christina Aungst, PharmD, MWC

Christina Aungst, PharmD, MWC is a senior pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019.

Reviewed by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

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