Paxlovid (Nirmatrelvir and Ritonavir) - Oral

What Is Paxlovid?

Paxlovid is not an FDA-approved medicine in the United States. The FDA has issued an Emergency Use Authorization (EUA) to make Paxlovid available during the coronavirus disease (COVID-19) pandemic.

Paxlovid is an investigational (being studied) antiviral medication used to treat mild to moderate COVID-19 in adults and children age 12 years or older (weighing at least 88 pounds) with positive results of direct SARS-CoV-2 viral testing who are at high risk of developing severe COVID-19, which may result in hospitalization or death. Because Paxlovid is still being studied, limited information is available on its safety and effectiveness in patients with mild to moderate COVID-19.

Paxlovid is available through a prescription only and comes as a dose pack containing two medications: nirmatrelvir tablets and ritonavir tablets. Nirmatrelvir works to block the main enzyme, Mpro, of the SARS-CoV-2 virus (the virus that causes COVID-19), preventing it from replicating inside the body. Ritonavir helps to prevent the metabolism of nirmatrelvir, allowing it to reach higher concentrations and work longer in the body.

Drug Facts

Generic Name: Nirmatrelvir and ritonavir

Brand Name(s): Paxlovid

Drug Availability: Prescription

Therapeutic Classification: Protease inhibitor

Available Generically: No

Controlled Substance: No

Administration Route: Oral

Active Ingredient: Nirmatrelvir and ritonavir

Dosage Form(s): Oral tablet

What Is Paxlovid Used For?

Paxlovid is an investigational (being studied) antiviral medication used to treat mild to moderate COVID-19 in adults and children age 12 years or older (weighing at least 88 pounds) with positive results of direct SARS-CoV-2 viral testing and who are at high risk of developing severe COVID-19, which may result in hospitalization or death. Paxlovid is not an FDA-approved medicine in the United States. It is still being studied and is allowed to be used during the COVID-19 pandemic only under the current Emergency Use Authorization (EUA) issued by the FDA.

How to Take Paxlovid

Start taking Paxlovid as soon as possible (within five days of your COVID-19 symptoms) for the treatment to work its best. Take Paxlovid by mouth as directed by your healthcare provider.

Paxlovid consists of two medications: nirmatrelvir tablets and ritonavir tablets. Nirmatrelvir is an oval pink tablet, and ritonavir is a white or off-white tablet. These two medications are taken two times a day for five days.

Paxlovid is available in two strengths: a 300 milligram (mg) and 100 milligram (mg) dose pack, and a 150 milligram (mg) and 100 milligram (mg) dose pack. Your healthcare provider will prescribe the optimal dose pack for you.

For the dose pack containing 300 milligram (mg) nirmatrelvir and 100 milligram (mg) ritonavir (each dose contains three tablets):

  • Morning dose: Take two pink nirmatrelvir tablets and one white to off-white ritonavir tablet together at the same time by mouth each morning.
  • Evening dose: Take two pink nirmatrelvir tablets and one white to off-white ritonavir tablet together at the same time by mouth each evening.

For the dose pack containing 150 milligram (mg) nirmatrelvir and 100 milligram (mg) ritonavir (each dose contains two tablets):

  • Morning dose: Take one pink nirmatrelvir tablet and one white to off-white ritonavir tablet together at the same time by mouth each morning.
  • Evening dose: Take one pink nirmatrelvir tablet and one white to off-white ritonavir tablet together at the same time by mouth each evening.

 While taking Paxlovid:

  • Do not remove your Paxlovid tablets from the blister card until you are ready to take your dose.
  • Take your first dose of Paxlovid in the morning or evening, depending on when you pick up your prescription or as recommended by your healthcare provider.
  • Swallow the tablets whole. Do not chew, break, or crush the tablets.
  • Paxlovid may be taken with or without food.
  • Do not stop taking Paxlovid without talking to your healthcare provider, even if you feel better.

Storage

Keep your medications tightly closed and out of the reach of children and pets, ideally locked in a cabinet or closet.

Store Paxlovid in a closed container at room temperature, away from heat, moisture, and direct light. Do not store your medication in the bathroom.

Avoid pouring unused and expired drugs down the drain or in the toilet. Ask your pharmacist or healthcare provider about the best ways to dispose of this medicine. Visit the FDA's website to know where and how to discard all unused and expired drugs. You can also find disposal boxes in your area. Ask your pharmacist or healthcare provider if you have any questions about the best ways to dispose of your medications.

If you travel with Paxlovid, get familiar with your final destination's regulations. In general, be sure to make a copy of your Paxlovid prescription. Keep your medication in its original container from your pharmacy with your name on the label. Ask your pharmacist or healthcare provider if you have any questions about traveling with your medicine.

Off-Label Uses

Paxlovid is not an FDA-approved medication. Under the FDA's current Emergency Use Authorization (EUA), Paxlovid is currently being prescribed off-label to treat mild to moderate COVID-19 in adults and children age 12 years or older (weighing at least 88 pounds) with positive results of direct SARS-CoV-2 viral testing and who are at high risk of developing severe COVID-19, which may result in hospitalization or death.

How Long Does Paxlovid Take to Work?

The time it takes Paxlovid to work may be different for everyone. Contact your healthcare provider or pharmacist with any questions.

What Are the Side Effects of Paxlovid?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or healthcare provider. You may report side effects to the Food and Drug Administration (FDA) at fda.gov/medwatch or 800-FDA-1088.

Limited data is available for Paxlovid, as it is still being studied. Not all risks may be understood completely. A healthcare provider can advise you on side effects.

Common Side Effects

Common side effects of Paxlovid include:

Severe Side Effects

Call your healthcare provider right away if you have serious side effects. Call 911 if your symptoms feel life threatening or if you think you have a medical emergency. Serious side effects and their symptoms can include the following:

Long-Term Side Effects

Long-term effects of Paxlovid are lacking.

Report Side Effects

Paxlovid may cause other side effects. Paxlovid is still being studied, so it is possible that all of the risks are not known at this time. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program online or by phone (800-332-1088).

Dosage: How Much Paxlovid Should I Take?

The dose of this medicine will be different for different people. Follow your healthcare provider's guidance or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your healthcare provider says to do so.

Modifications

The following modifications should be kept in mind when using Paxlovid:

Pregnancy or breastfeeding: Adverse events were observed following exposure to nirmatrelvir in some studies. If pregnant or breastfeeding, please talk with your healthcare provider before starting Paxlovid.

Adults over 65: Clinical studies haven't included a large enough number of people in this age group to see whether they respond differently from younger adults.

Children: Paxlovid is not authorized for use in children younger than 12 years of age or weighing less than 88 pounds.

Kidney problems: If you have kidney disease, your healthcare provider may prescribe a lower dose. Talk to your healthcare provider to ensure you receive the correct dose pack.

Missed Dose

If you miss your dose of Paxlovid within eight hours of the time it is usually taken, take it as soon as you remember. If you forget your dose by more than eight hours, skip the missed dose and take the next dose at your regular time. Do not take two doses of Paxlovid at the same time.

Overdose: What Happens If I Take Too Much Paxlovid?

If you take too much Paxlovid, call your healthcare provider or go to the nearest hospital emergency room right away.

There is limited information available about Paxlovid overdose.

If you think you're experiencing an overdose or life-threatening symptoms, seek immediate medical attention.

What Happens If I Overdose on Paxlovid?

If you think you or someone else may have overdosed on Paxlovid, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Paxlovid, call 911 immediately.

Precautions

Your healthcare provider is available to discuss any precautions with you. Be sure to ask your prescriber or pharmacist any questions you may have.

What Are Reasons I Shouldn’t Take Paxlovid?

You should not take Paxlovid if you have one of the following:

If you're allergic to nirmatrelvir, ritonavir, or any of the ingredients in Paxlovid. Ask your pharmacist or healthcare provider for a complete list of the ingredients if you're unsure.

If you take any of the following medications, which may cause serious or life-threatening side effects or may affect how well Paxlovid works:

  • Uroxatral (alfuzosin)
  • Pacerone (amiodarone)
  • Erleada (apalutamide)
  • Tegretol (carbamazepine)
  • Versacloz (clozapine)
  • Mitigare (colchicine)
  • Migranal (dihydroergotamine)
  • Multaq (dronedarone)
  • Relpax (eletriptan)
  • Inspra (eplerenone)
  • Ergomar (ergotamine)
  • Kerendia (finerenone)
  • Tambocor (flecainide)
  • Addyi (flibanserin)
  • Corlanor (ivabradine)
  • Juxtapid (lomitapide)
  • Mevacor (lovastatin)
  • Orkambi (lumacaftor/ivacaftor)
  • Latuda (lurasidone)
  • Methergine (methylergonovine)
  • Versed (midazolam (oral))
  • Movantik (naloxegol)
  • Demerol (pethidine)
  • Solfoton (phenobarbital)
  • Dilantin (phenytoin)
  • Orap (pimozide)
  • Mysoline (primidone)
  • Rythmol (propafenone)
  • Cardioquin (quinidine)
  • Ranexa (ranolazine)
  • Rifadin (rifampin)
  • Revatio (sildenafil for pulmonary arterial hypertension)
  • Rapaflo (silodosin)
  • Zocor (simvastatin)
  • St. John’s Wort (Hypericum perforatum)
  • Samsca, Jynarque (tolvaptan)
  • Halcion (triazolam)
  • Ubrelvy (ubrogepant)
  • Lupkynis (voclosporin)

Please let your healthcare provider know if you have kidney disease, liver disease, or HIV infection because taking Paxlovid may worsen your condition.

What Other Medications Interact With Paxlovid?

Several medications can affect how Paxlovid works. Please tell your doctor if you are taking any of the following medications:

  • Tekturna, Rasilez (aliskiren)
  • Lipitor (atorvastatin)
  • Stendra (avanafil)
  • Sirturo (bedaquiline)
  • Tracleer and Safebo (bosentan)
  • Plavix (clopidogrel)
  • Neoral (cyclosporine)
  • Exviera (dasabuvir)
  • Digox (digoxin)
  • Zepatier (elbasvir/grazoprevir)
  • Trikafta (elexacaftor/tezacaftor/ivacaftor)
  • Afinitor (everolimus)
  • Duragesic (fentanyl)
  • Mavyret (glecaprevir/pibrentasvir)
  • Hysingla ER (hydrocodone)
  • Kalydeco (ivacaftor)
  • Xylocaine (lidocaine)
  • Dolophine (methadone)
  • Technivie (ombitasvir/paritaprevir/ritonavir)
  • Xtampza ER (oxycodone)
  • Seroquel (quetiapine)
  • Mycobutin (rifabutin)
  • Priftin (rifapentine)
  • Nurtec ODT (rimegepant)
  • Crestor (rosuvastatin)
  • Serevent (salmeterol)
  • Rapamune (sirolimus)
  • Vosevi (sofosbuvir/velpatasvir/voxilaprevir)
  • Belsomra (suvorexant)
  • Prograf (tacrolimus)
  • Cialis (tadalafil)
  • Flomax (tamsulosin)
  • Symdeko (tezacaftor/ivacaftor)
  • Brilinta (ticagrelor)
  • Levitra (vardenafil)
  • Zontivity (vorapaxar)
  • Birth control pills (including ethinyl estradiol)
  • Blood pressure medicine (including Norvasc (amlodipine), Cardizem (diltiazem), Plendil (felodipine), Cardene (nicardipine), Procardia (nifedipine))
  • Blood thinner (including Pradaxa (dabigatran), Xarelto (rivaroxaban), and Coumadin (warfarin))
  • Medicine to treat cancer (including Verzenio (abemaciclib), Zykadia (ceritinib), Sprycel (dasatinib), Braftovi (encorafenib), Imbruvica (ibrutinib), Imbruvica (ivosidenib), Nerlynx (neratinib), Tasigna (nilotinib), Venclexta (venetoclax), Velban (vinblastine), Oncovin (vincristine))
  • Medicine to treat depression (including Aplenzin (bupropion) and Desyrel (trazodone))
  • Medicine to treat HIV (including Reyataz (atazanavir), Biktarvy (bictegravir/emtricitabine/tenofovir), Prezista (darunavir), Sustiva (efavirenz), Selzentry (maraviroc), Aptivus (tipranavir), Retrovir (zidovudine))
  • Medicine to treat infections (including Biaxin (clarithromycin), Emgel (erythromycin), Cresemba (isavuconazonium), Sporanox (itraconazole), Nizoral (ketoconazole), Vfend (voriconazole))
  • Steroid medicine (including Celestone (betamethasone), Pulmicort (budesonide), Omnaris (ciclesonide), Decadron (dexamethasone), Veramyst (fluticasone), Medrol (methylprednisolone), Elocon (mometasone), Aristocort (triamcinolone))

This is not a complete list of medications that interact with Paxlovid. 

Talk with your pharmacist or healthcare provider for more detailed information about medication interactions with Paxlovid. 

Talk with your healthcare provider about any other medicines you take or plan to take, including over-the-counter, nonprescription products, vitamins, herbs, or plant-based medicines.

If you take hormonal birth control pills, Paxlovid may affect how well your birth control works to prevent pregnancy. If you do not plan on becoming pregnant, you should use another form of birth control such as condoms or spermicide with your birth control pills while taking Paxlovid.

What Medications Are Similar?

There are no comparable medications to Paxlovid at this time.

Frequently Asked Questions

  • What is Paxlovid used for?

    Paxlovid is an investigational antiviral medication used to treat mild to moderate COVID-19 in adults and children age 12 years or older (weighing at least 88 pounds) with positive results of direct SARS-CoV-2 viral testing and who are at high risk of developing severe COVID-19, which may result in hospitalization or death.

  • What is SARS-CoV-2?

    The virus that causes coronavirus disease (COVID-19).

  • Is Paxlovid FDA approved?

    No, Paxlovid is not FDA approved.

  • What is an Emergency Use Authorization (EUA)?

    In issuing a EUA under the COVID-19 public health emergency, the FDA has mainly determined and agreed upon the following:

    • Based on the total amount of scientific evidence available (including data from adequate and well-controlled clinical trials, if available), it is reasonable to believe that the product may be effective for diagnosing, treating, or preventing COVID-19 or a severe or life-threatening disease or condition caused by COVID-19.
    • The known and potential benefits of the product, when used to diagnose, treat, or prevent such disease or condition, outweigh the known and potential risks.
    • There are no adequate, approved, and available alternatives.

    The EUA for Paxlovid is in effect only for the duration of the COVID-19 declaration justifying emergency use of this product.

How Can I Stay Healthy While Taking Paxlovid?

Testing positive for SARS-CoV-2 (the virus that causes coronavirus or COVID-19) can undoubtedly come with its challenges. Paxlovid may be able to prevent your mild to moderate COVID-19 symptoms from becoming severe and life-threatening. Refer below for some general tips to support your health while taking Paxlovid and having COVID-19:

  • Take Paxlovid as recommended by your healthcare provider.
  • Complete the entire five-day treatment course of the medication and follow quarantine guidelines as outlined by the CDC to prevent the spread of SARS-CoV-2 to others
  • Talk to your healthcare provider if you do not feel better or feel worse after five days.
  • Get rest and stay hydrated.
  • Monitor your symptoms. If at any point your symptoms become severe, seek medical attention immediately (trouble breathing; persistent pain or pressure in the chest; new confusion; inability to wake or stay awake; pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone)
  • Suppose you take ritonavir- or cobicistat-containing medicine to treat hepatitis C or Human Immunodeficiency Virus (HIV). In that case, you should continue to take your medication as prescribed by your healthcare provider.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s).

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Drug Administration. EUA Paxlovid fact sheet.

  2. Hammond J, Leister-Tebbe H, Gardner A, et al. Oral nirmatrelvir for high-risk, nonhospitalized adults with COVID-19N Engl J Med. 2022;386(15):1397-1408. doi:10.1056/NEJMoa2118542