Nirmatrelvir / Ritonavir

DRUG INFORMATION

  ADULT
    - ( 2.2 , 2.3 ) • Dosage: 300 mg nirmatrelvir (two 150 mg tablets) with 100 mg
      ritonavir (one 100 mg tablet), with all 3 tablets taken together twice daily for 5
      days.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29
    - PAXLOVID is nirmatrelvir tablets co-packaged with ritonavir tablets. ( 2.1 )
      Nirmatrelvir must be co-administered with ritonavir. ( 2.1 ) • Initiate PAXLOVID
      treatment as soon as possible after diagnosis of COVID-19 and within 5 days of
      symptom onset. ( 2.1 ) • Administer orally with or without food. ( 2.1 ) •
      Administer at approximately the same time each day.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29

  CHILD
    - The optimal dose of PAXLOVID has not been established in pediatric patients.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'pediatric use',
      retrieved 2026-08-29
    - PAXLOVID is nirmatrelvir tablets co-packaged with ritonavir tablets. ( 2.1 )
      Nirmatrelvir must be co-administered with ritonavir. ( 2.1 ) • Initiate PAXLOVID
      treatment as soon as possible after diagnosis of COVID-19 and within 5 days of
      symptom onset. ( 2.1 ) • Administer orally with or without food. ( 2.1 ) •
      Administer at approximately the same time each day.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29
    - Day 1 300 mg nirmatrelvir (two 150 mg tablets) with 100 mg ritonavir (one 100 mg
      tablet) once Days 2-5 150 mg nirmatrelvir (one 150 mg tablet) with 100 mg
      ritonavir (one 100 mg tablet) once daily • PAXLOVID is not recommend in patients
      with severe hepatic impairment (Child-Pugh Class C).
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29

  RENAL IMPAIRMENT
    - ( 2.2 ) • Dose Reduction for Renal Impairment ( 2.3 , 8.6 , 12.3 ) Abbreviation:
      eGFR=estimated glomerular filtration rate.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29
    - Moderate renal impairment (eGFR ≥30 to <60 mL/min) Days 1-5 150 mg nirmatrelvir
      (one 150 mg tablet) with 100 mg ritonavir (one 100 mg tablet) twice daily Severe
      renal impairment (eGFR <30 mL/min) including those requiring hemodialysis On days
      of hemodialysis, the PAXLOVID dose should be administered after hemodialysis.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29
    - There are three different dose packs available: • PAXLOVID (nirmatrelvir;
      ritonavir) co-packaged for oral use 300 mg;100 mg [see Dosage and Administration
      (2.2) ] . • PAXLOVID (nirmatrelvir; ritonavir) co-packaged for oral use 150 mg;100
      mg for patients with moderate renal impairment [see Dosage and Administration
      (2.3) ].
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29

  HEPATIC IMPAIRMENT
    - Day 1 300 mg nirmatrelvir (two 150 mg tablets) with 100 mg ritonavir (one 100 mg
      tablet) once Days 2-5 150 mg nirmatrelvir (one 150 mg tablet) with 100 mg
      ritonavir (one 100 mg tablet) once daily • PAXLOVID is not recommend in patients
      with severe hepatic impairment (Child-Pugh Class C).
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29
    - Day 1 300 mg nirmatrelvir (two 150 mg tablets) with 100 mg ritonavir (one 100 mg
      tablet) once Days 2-5 150 mg nirmatrelvir (one 150 mg tablet) with 100 mg
      ritonavir (one 100 mg tablet) once daily 2.4 Use in Patients with Hepatic
      Impairment No dosage adjustment is needed in patients with mild (Child-Pugh Class
      A) or moderate (Child-Pugh Class B) hepatic impairment.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29
    - No pharmacokinetic or safety data are available regarding the use of nirmatrelvir
      or ritonavir in subjects with severe (Child-Pugh Class C) hepatic impairment;
      therefore, PAXLOVID is not recommended for use in patients with severe hepatic
      impairment [see Use in Specific Populations (8.7) ] .
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'dosage and
      administration', retrieved 2026-08-29

  PREGNANCY
    - Risk Summary 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.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'pregnancy', retrieved
      2026-08-29
    - Published observational studies on ritonavir use in pregnant women have not
      identified an increase in the risk of major birth defects.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'pregnancy', retrieved
      2026-08-29
    - Published studies with ritonavir are insufficient to identify a drug associated
      risk of miscarriage (see Data ).
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'pregnancy', retrieved
      2026-08-29

  BREASTFEEDING
    - A pre- and postnatal developmental (PPND) study in pregnant rats administered oral
      nirmatrelvir doses of up to 1,000 mg/kg/day from GD 6 through Lactation Day (LD)
      20 showed no adverse findings.
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'use in specific
      populations', retrieved 2026-08-29
    - In a PPND study in rats, administration of 0, 15, 35, and 60 mg/kg/day ritonavir
      from GD 6 through PND 20 resulted in no developmental toxicity, at ritonavir
      systemic exposures greater than 10 times the exposure at the approved human dose
      of PAXLOVID. 8.2 Lactation Risk Summary Nirmatrelvir and ritonavir are present in
      human breast milk in small amounts (less than 2%).
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'use in specific
      populations', retrieved 2026-08-29
    - In a clinical lactation study in 8 lactating women, nirmatrelvir and ritonavir
      were estimated to be present in human milk at a mean weight-normalized infant
      daily dose of 0.16 mg/kg/day (1.8% of maternal weight-adjusted daily dose) and
      0.006 mg/kg/day (0.2% of maternal weight-adjusted daily dose), respectively (see
      Data ) .
      Source: US FDA label for nirmatrelvir (Paxlovid), section 'use in specific
      populations', retrieved 2026-08-29