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About PAXLOVIDAbout PAXLOVID

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When to TreatHigh-Risk FactorsMechanism of ActionDosingEfficacy & Real-World EvidenceEfficacy & Real-World Evidence

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EPIC-HR TrialEPIC-HR ResultsReal-World EvidenceSafetySafety

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Adverse ReactionsDrug InteractionsViral ReboundAccess & ResourcesAccess & Resources

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Access & ResourcesDownload Co-Pay CardResourcesRegister for PAXLOVID UpdatesFrequently Asked Questions
Full Prescribing Information and Patient InformationIndication HCP EUA WebsitePatient Website
Frequently Asked Questions How soon after my patient begins experiencing symptoms should they initiate treatment with PAXLOVID?

The 5-day treatment course of PAXLOVID should be initiated as soon as possible after a diagnosis of COVID‑19 has been made and within 5 days of symptom onset even if baseline COVID-19 symptoms are mild.1

For more information about product dosage, see Section 2: Dosage and Administration in the Full Prescribing Information here.

What is the recommended dosage? Is there any important dosing information my patient should be aware of?

Standard dosage
The standard dosage for PAXLOVID is 2 nirmatrelvir 150 mg tablets and 1 ritonavir 100 mg tablet taken together in the morning and at bedtime, with or without food, for 5 days. PAXLOVID should be administered at approximately the same time each day for 5 days. Prescriptions should specify the numeric dose of each active ingredient within PAXLOVID. Completion of the full 5-day treatment course and continued isolation in accordance with public health recommendations are important to maximize viral clearance and minimize transmission of SARS-CoV-2.1

Dosage in patients with renal impairment
No dosage adjustment is needed in patients with mild renal impairment (eGFR ≥60 to <90 mL/min).1

In patients with moderate renal impairment (eGFR ≥30 to <60 mL/min), the dosage of PAXLOVID is 1 nirmatrelvir 150 mg tablet and 1 ritonavir 100 mg tablet taken together in the morning and at bedtime, with or without food, for 5 days. PAXLOVID should be administered at approximately the same time each day.1

In patients with severe renal impairment (eGFR <30 mL/min, including those requiring hemodialysis), the dosage of PAXLOVID is1In patients with severe renal impairment (eGFR <30 mL/min, including those requiring hemodialysis), the dosage of PAXLOVID is1:
  • Day 1: 2 nirmatrelvir 150 mg tablets (300 mg) and 1 ritonavir 100 mg tablet taken together
  • Days 2 to 5: 1 nirmatrelvir 150 mg tablet and 1 ritonavir 100 mg tablet taken together
  • PAXLOVID should be administered at approximately the same time each day for 5 days
  • On days of hemodialysis, the PAXLOVID dose should be administered after hemodialysis

Prescriptions should specify the numeric dose of each active ingredient within PAXLOVID. Healthcare providers should counsel patients about renal dosing instructions.1

  • Patients should swallow the tablets whole. They should not chew, break, or crush the tablets
  • Patients can take PAXLOVID with or without food
  • Even if patients feel better, they should not stop taking PAXLOVID without talking to the prescribing healthcare provider
  • Alert the patient to the importance of completing the full 5-day treatment course and to continue isolation in accordance with public health recommendations to maximize viral clearance and minimize transmission of SARS-CoV-2
Use in patients with hepatic impairment​​
No dosage adjustment is recommended in patients with mild (Child-Pugh Class A) or moderate (Child-Pugh Class B) hepatic impairment.1No pharmacokinetic or safety data are available regarding the use of nirmatrelvir or ritonavir in subjects with severe hepatic impairment (Child-Pugh Class C); therefore, PAXLOVID is not recommended for use in patients with severe hepatic impairment.1For more information about product dosage, see Section 2: Dosage and Administration in the Prescribing Information here.Which dosing option is appropriate for patients with moderate renal impairment?

Renal impairment increases nirmatrelvir exposure, which may increase the risk of PAXLOVID adverse reactions.1

Prescribe the Reduced Dose Pack to patients with moderate renal impairment (eGFR ≥30 to <60 mL/min). This dosage of PAXLOVID is 1 nirmatrelvir 150 mg tablet and 1 ritonavir 100 mg tablet taken together in the morning and at bedtime, with or without food, for 5 days. PAXLOVID should be administered at approximately the same time each day.1Prescriptions should specify the numeric dose of each active ingredient within PAXLOVID. Healthcare providers should counsel patients about renal dosing instructions.1What are the contraindications for PAXLOVID?

PAXLOVID is contraindicated in/with1:

  • Patients with a history of clinically significant hypersensitivity reactions (eg, toxic epidermal necrolysis or Stevens-Johnson syndrome) to its active ingredients (nirmatrelvir or ritonavir) or any other components of the product
  • Drugs that are primarily metabolized by CYP3A and for which elevated concentrations are associated with serious and/or life-threatening reactions:
    • Alpha 1-adrenoreceptor antagonist: alfuzosin

    • Antianginal: ranolazine

    • Antiarrhythmic: amiodarone, dronedarone, flecainide, propafenone, quinidine

    • Anti-gout: colchicine (in patients with renal and/or hepatic impairment)
    • Antipsychotics: lurasidone, pimozide
    • Benign prostatic hyperplasia agents: silodosin

    • Cardiovascular agents: eplerenone, ivabradine

    • Ergot derivatives: dihydroergotamine, ergotamine, methylergonovine

    • HMG-CoA reductase inhibitors: lovastatin, simvastatin (these drugs can be
 temporarily discontinued to allow PAXLOVID use)
    • Immunosuppressants: voclosporin
    • Microsomal triglyceride transfer protein inhibitor: lomitapide

    • Migraine medications: eletriptan, ubrogepant
    • Mineralocorticoid receptor antagonists: finerenone
    • Opioid antagonists: naloxegol

    • PDE5 inhibitor: sildenafil (Revatio®) when used for pulmonary arterial hypertension
 (PAH)

    • Sedative/hypnotics: triazolam, oral midazolam

    • Serotonin receptor 1A agonist/serotonin receptor 2A antagonist: flibanserin

    • Vasopressin receptor antagonists: tolvaptan 
  • Drugs that are strong CYP3A inducers where significantly reduced nirmatrelvir or ritonavir plasma concentrations may be associated with the potential for loss of virologic response and possible resistance. PAXLOVID cannot be started immediately after discontinuation of any of the following medications due to the delayed offset of the recently discontinued CYP3A inducer

    • Anticancer drugs: apalutamide, enzalutamide

    • Anticonvulsant: carbamazepine, phenobarbital, primidone, phenytoin

    • Antimycobacterials: rifampin, rifapentine

    • Cystic fibrosis transmembrane conductance regulator potentiators: lumacaftor/
 ivacaftor

    • Herbal products: St. John's Wort (hypericum perforatum)
What are the potential drug interactions with PAXLOVID?

See a list of established and other potentially significant drug interactions here.

PAXLOVID (nirmatrelvir co-packaged with ritonavir) is a strong inhibitor of CYP3A, and an inhibitor of CYP2D6, P-gp, and OATP1B1. Co-administration of PAXLOVID with drugs that are primarily metabolized by CYP3A and CYP2D6 or are transported by P-gp or OATP1B1 may result in increased plasma concentrations of such drugs and increase the risk of adverse events. Co-administration of PAXLOVID with drugs highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events is contraindicated. Co-administration with other CYP3A substrates may require a dose adjustment or additional monitoring as shown in Table 2.1Nirmatrelvir and ritonavir are CYP3A substrates; therefore, drugs that induce CYP3A may decrease nirmatrelvir and ritonavir plasma concentrations and reduce PAXLOVID therapeutic effect.1For a list of clinically significant drug interactions, including contraindicated drugs, refer to Section 7, Table 2: Established and Other Potentially Significant Drug Interactions here.What if patients take PAXLOVID incorrectly?

Missed dose: If the patient misses a dose of PAXLOVID within 8 hours of the time it is usually taken, the patient should take it as soon as possible and resume the normal dosing schedule. If the patient misses a dose by more than 8 hours, the patient should not take the missed dose and instead take the next dose at the regularly scheduled time. The patient should not double the dose to make up for a missed dose.1

Overdose: If patients overdose on PAXLOVID, they should call their prescribing healthcare provider or go to the nearest hospital emergency room right away. Treatment of overdose with PAXLOVID should consist of general supportive measures including monitoring of vital signs and observation of the clinical status of the patient. There is no specific antidote for overdose with PAXLOVID.1For more information on product dosage, see Section 2: Dosage and Administration and Section 10: Overdosage in the Prescribing Information here.How can I help patients save on PAXLOVID?With the PAXCESS® Co-Pay Savings Program, eligible prescribed patients with commercial insurance may pay as little as $0* for their PAXLOVID prescription.Eligible Medicare, Medicaid, and uninsured patients may access PAXLOVID for free† through the US Government Patient Assistance Program (USG PAP).Please visit the access page to learn more.*Eligible commercially insured patients can save up to $1,500 per prescription. Maximum annual savings up to $1,500. Full terms and conditions apply. Please click here for full terms and conditions.
†The USG PAP operated by Pfizer will continue to provide eligible patients on Medicare, Medicaid, TRICARE, Veteran Affairs Community Care Network, and those who are uninsured access to PAXLOVID for free through December 31, 2025. PAXLOVID, through the USG PAP, is not available to patients who have commercial prescription drug health insurance. The USG PAP operated by Pfizer is an independent program with separate eligibility requirements offered by the US Department of Health and Human Services and is not owned by Pfizer. Full terms and conditions for the USG PAP can be found here.What risk factors put my patients at high risk for severe COVID-19?Studies have shown that COVID-19 does not affect all populations equally. Age remains the strongest risk factor for progressing to severe COVID-19 (age 50+). In addition, the COVID-19 pandemic has highlighted racial, ethnic, and socioeconomic disparities in COVID-19 illnesses, hospitalizations, and deaths due to multiple factors, including barriers to accessing health care.2

Additionally, being unvaccinated or not being up to date on COVID-19 vaccinations also increases the risk of severe COVID-19 outcomes.2

Providers should consider the patient’s age, presence of underlying medical conditions and other risk factors, and vaccination status in determining the risk of severe COVID-19–associated outcomes for any patient.2

Underlying medical conditions and factors associated with high risk for severe COVID-19 include2:

Higher risk (conclusive evidence)

  • Asthma
  • Cancer
  • Hematologic malignancies
  • Cerebrovascular disease
  • Chronic kidney disease*

    • People receiving dialysis†
  • Chronic lung diseases, limited to:

    • Bronchiectasis

    • COPD (chronic obstructive pulmonary disease)

    • Interstitial lung disease

    • Pulmonary embolism

    • Pulmonary hypertension
  • Chronic liver diseases, limited to:

    • Cirrhosis

    • Nonalcoholic fatty liver disease
    • Alcoholic liver disease

    • Autoimmune hepatitis
  • Cystic fibrosis
  • Diabetes mellitus type 1
  • Diabetes mellitus type 2*
  • Disabilities, including Down syndrome
  • Heart conditions (such as heart failure, coronary artery disease, or cardiomyopathies)
  • HIV
  • Mental health conditions limited to:

    • Mood disorders, including depression

    • Schizophrenia spectrum disorders
  • Neurologic conditions limited to dementia
  • Obesity (BMI ≥30 kg/m2 or ≥95th percentile in children)
  • Physical inactivity
  • Pregnancy and recent pregnancy
  • Primary immunodeficiencies
  • Smoking, current and former
  • Solid organ or blood stem cell transplantation
  • Tuberculosis
  • Use of corticosteroids or other immunosuppressive medications
Suggestive higher risk‡
  • Overweight (BMI ≥25 kg/m2, but <30 kg/m2)
  • Sickle cell disease
  • Substance use disorders
Mixed evidence (inconclusive: no conclusions can be drawn from the evidence)
  • Alpha-1 antitrypsin deficiency
  • Bronchopulmonary dysplasia
  • Hepatitis B and C
  • Hypertension*
  • Thalassemia
Consult the CDC for the latest information on risk factors:
https://www.cdc.gov/covid/hcp/clinical-care/underlying-conditions.html?CDC_AAref_Val=https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-care/underlyingconditions.html.§*Indicates presence of evidence for pregnant and nonpregnant people.2
†Risk may be further increased for people receiving dialysis.2
‡The language expressed on this page is consistent with CDC guidance, with the exception of risk factors regarding pediatric patients, which were removed from this list. PAXLOVID is not approved for use in pediatric patients.1
§This link will take you to a website that is owned and operated by the CDC. Pfizer is not responsible for the content or services of this site.Who can I contact for support?

For medical questions related to PAXLOVID, you can visit pfizermedicalinformation.com or call Medical Information at 1-800-438-1985.

Access & Resources Looking for Additional Resources?

Download the latest PAXLOVID materials

 Explore resources LoadingBMI=body mass index; CDC=Centers for Disease Control and Prevention; CYP3A=cytochrome P450, family 3, subfamily A; eGFR=estimated glomerular filtration rate; HMG-CoA=3-hydroxy-3-methylglutaryl-coenzyme A; OATP181=organic anion transporting polypeptides 181; P-gp=P-glycoprotein; SARS-CoV-2=severe acute respiratory syndrome coronavirus 2.References:PAXLOVID Prescribing Information. Pfizer Inc.; 2025.Underlying conditions and the higher risk for severe COVID-19. Centers for Disease Control and Prevention. Accessed July 31, 2025. https://www.cdc.gov/covid/hcp/clinical-care/underlying-conditions.html

To report an adverse event, please call 1-800-438-1985

Pfizer for Professionals 1-800-505-4426

This site is intended only for U.S. healthcare professionals. The products discussed in this site may have different product labeling in different countries. The information provided is for educational purposes only.

© 2025 Pfizer Inc. All rights reserved.

PP-C1D-USA-1822
Important Safety Information
 WARNING: SIGNIFICANT DRUG INTERACTIONS WITH PAXLOVID
  • PAXLOVID includes ritonavir, a strong CYP3A inhibitor, which may lead to greater exposure of certain concomitant medications, resulting in potentially severe, life-threatening, and/or fatal events
  • Prior to prescribing PAXLOVID: 1) Review all medications taken by the patient to assess for potential drug-drug interactions with a strong CYP3A inhibitor like PAXLOVID and 2) Determine if concomitant medications require a dose adjustment, interruption, and/or additional monitoring
  • Consider the benefit of PAXLOVID treatment in reducing hospitalization and death, and whether the risk of potential drug-drug interactions for an individual patient can be appropriately managed
PAXLOVID is contraindicated in patients with a history of clinically significant hypersensitivity reactions (eg, toxic epidermal necrolysis or Stevens-Johnson syndrome) to its active ingredients (nirmatrelvir or ritonavir) or any other components of the product. If signs and symptoms of a clinically significant hypersensitivity reaction or anaphylaxis occur, immediately discontinue PAXLOVID and initiate appropriate medications and/or supportive care. PAXLOVID is contraindicated with drugs that are primarily metabolized by CYP3A and for which elevated concentrations are associated with serious and/or life-threatening reactions and drugs that are strong CYP3A inducers where significantly reduced nirmatrelvir or ritonavir plasma concentrations may be associated with the potential for loss of virologic response and possible resistance. There are certain other drugs for which concomitant use with PAXLOVID should be avoided and/or dose adjustment, interruption, or therapeutic monitoring is recommended. Drugs listed here are a guide and not considered a comprehensive list of all drugs that may be contraindicated with PAXLOVID. The healthcare provider should consult other appropriate resources such as the prescribing information for the interacting drug for comprehensive information on dosing or monitoring with concomitant use of a strong CYP3A inhibitor like PAXLOVID. Drugs that are primarily metabolized by CYP3A for which elevated concentrations are associated with serious and/or life-threatening reactions:
  • Alpha 1-adrenoreceptor antagonist: alfuzosin
  • Antianginal: ranolazine
  • Antiarrhythmic: amiodarone, dronedarone, flecainide, propafenone, quinidine
  • Anti-gout: colchicine (in patients with renal and/or hepatic impairment)
  • Antipsychotics: lurasidone, pimozide
  • Benign prostatic hyperplasia agents: silodosin
  • Cardiovascular agents: eplerenone, ivabradine
  • Ergot derivatives: dihydroergotamine, ergotamine, methylergonovine
  • HMG-CoA reductase inhibitors: lovastatin, simvastatin (these drugs can be temporarily discontinued to allow PAXLOVID use)
  • Immunosuppressants: voclosporin
  • Microsomal triglyceride transfer protein inhibitor: lomitapide
  • Migraine medications: eletriptan, ubrogepant
  • Mineralocorticoid receptor antagonists: finerenone
  • Opioid antagonists: naloxegol
  • PDE5 inhibitor: sildenafil (Revatio®) when used for pulmonary arterial hypertension
  • Sedative/hypnotics: triazolam, oral midazolam
  • Serotonin receptor 1A agonist/serotonin receptor 2A antagonist: flibanserin
  • Vasopressin receptor antagonists: tolvaptan

Drugs that are strong CYP3A inducers: PAXLOVID cannot be started immediately after discontinuation of any of the following medications due to the delayed offset of the recently discontinued CYP3A inducer:

  • Anticancer drugs: apalutamide, enzalutamide
  • Anticonvulsant: carbamazepine, phenobarbital, primidone, phenytoin
  • Antimycobacterials: rifampin, rifapentine
  • Cystic fibrosis transmembrane conductance regulator potentiators: lumacaftor/ivacaftor
  • Herbal Products: St. John’s Wort (hypericum perforatum)
 Risk of Serious Adverse Reactions Due to Drug Interactions: Initiation of PAXLOVID, which contains ritonavir, a strong CYP3A inhibitor, in patients receiving medications metabolized by CYP3A or initiation of medications metabolized by CYP3A in patients already receiving PAXLOVID, may increase plasma concentrations of medications metabolized by CYP3A. Medications that induce CYP3A may decrease concentrations of PAXLOVID. These interactions may lead to:
  • Clinically significant adverse reactions, potentially leading to severe, life-threatening, or fatal events from greater exposures of concomitant medications
  • Loss of therapeutic effect of PAXLOVID and possible development of viral resistance
Severe, life-threatening, and/or fatal adverse reactions due to drug interactions have been reported in patients treated with PAXLOVID. The most commonly reported concomitant medications resulting in serious adverse reactions were calcineurin inhibitors (eg, tacrolimus, cyclosporine), followed by calcium channel blockers. Hepatotoxicity: Hepatic transaminase elevations, clinical hepatitis, and jaundice have occurred in patients receiving ritonavir. Therefore, caution should be exercised when administering PAXLOVID to patients with pre-existing liver diseases, liver enzyme abnormalities, or hepatitis. Because nirmatrelvir is coadministered with ritonavir, there may be a risk of HIV-1 developing resistance to HIV protease inhibitors in individuals with uncontrolled or undiagnosed HIV-1 infection. The most common adverse reactions in the PAXLOVID group (≥1%) that occurred at a greater frequency than in the placebo group were dysgeusia (5% and <1%, respectively) and diarrhea (3% and 2%, respectively). The following adverse reactions have been identified during use of PAXLOVID under Emergency Use Authorization: Immune System Disorders: Anaphylaxis, hypersensitivity reactions Skin and Subcutaneous Tissue Disorders: Toxic epidermal necrolysis, Stevens-Johnson syndrome Nervous System Disorders: Headache Vascular Disorders: Hypertension Gastrointestinal Disorders: Abdominal pain, nausea, vomiting General Disorders and Administration Site Conditions: Malaise PAXLOVID is a strong inhibitor of CYP3A, and an inhibitor of CYP2D6, P-gp, and OATP1B1. Coadministration of PAXLOVID with drugs that are primarily metabolized by CYP3A and CYP2D6 or are transported by P-gp or OATP1B1 may result in increased plasma concentrations of such drugs and increase the risk of adverse events. Coadministration with other CYP3A substrates may require a dose adjustment or additional monitoring.Pregnancy: Available data on the use of nirmatrelvir during pregnancy are insufficient to evaluate for a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Published observational studies on ritonavir use in pregnant women have not identified an increase in the risk of major birth defects. Published studies with ritonavir are insufficient to identify a drug-associated risk of miscarriage. There are maternal and fetal risks associated with untreated COVID-19 in pregnancy.Lactation: Nirmatrelvir and ritonavir are present in human breast milk in small amounts (less than 2%). There are no available data on the effects of nirmatrelvir or ritonavir on the breastfed infant or on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for PAXLOVID and any potential adverse effects on the breastfed infant from PAXLOVID or from the underlying maternal condition.Contraception: Use of ritonavir may reduce the efficacy of combined hormonal contraceptives. Advise patients using combined hormonal contraceptives to use an effective alternative contraceptive method or an additional barrier method of contraception. Pediatrics: The optimal dose of PAXLOVID has not been established in pediatric patients. Renal impairment increases nirmatrelvir exposure. Reduce the PAXLOVID dosage in patients with moderate renal impairment (eGFR ≥30 to <60 mL/min). Reduce the dose and dose frequency in patients with severe renal impairment (eGFR <30 mL/min), including those requiring hemodialysis. On days when patients undergo hemodialysis, the PAXLOVID dose should be administered after hemodialysis. Prescriptions should specify the numeric dose of each active ingredient within PAXLOVID. Providers should counsel patients about renal dosing instructions. PAXLOVID is not recommended for use in patients with severe hepatic impairment (Child-Pugh Class C). Please see Full Prescribing Information, including BOXED WARNING and Patient Information IndicationINDICATIONPAXLOVID is indicated for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in adults who are at high risk for progression to severe COVID-19, including hospitalization or death.Limitations of UsePAXLOVID is not approved for use as pre-exposure or post-exposure prophylaxis for prevention of COVID-19.Please see Full Prescribing Information, including BOXED WARNING and Patient Information
Indication PAXLOVID is indicated for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in adults who are at high risk for progression to severe COVID-19, including hospitalization or death.

Limitations of Use

PAXLOVID is not approved for use as pre-exposure or post-exposure prophylaxis for prevention of COVID-19.

Please see Full Prescribing Information, including BOXED WARNING and Patient Information