Overview
11 DESCRIPTION PAXLOVID is nirmatrelvir tablets co-packaged with ritonavir tablets. Nirmatrelvir is a SARS-CoV-2 main protease (M pro ) inhibitor, and ritonavir is an HIV-1 protease inhibitor and CYP3A inhibitor. Nirmatrelvir The chemical name of active ingredient of nirmatrelvir is (1 R ,2 S ,5 S )- N -((1 S )-1-Cyano-2-((3 S )-2-oxopyrrolidin-3-yl)ethyl)-3-((2 S...
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Nirmatrelvir is a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antiviral drug [see Microbiology (12.4) ]. Ritonavir is an HIV-1 protease inhibitor but is not active against SARS-CoV-2 M pro . Ritonavir inhibits the CYP3A-mediated metabolism of nirmatrelvir, resulting in increased plasma concentrations of nirmatrelvir. 12.2 Pharmacodynamics Cardiac Electrophysiology At 3 times the steady state peak plasma concentration (C max ) at the recommended dose, nirmatrelvir does not prolong the QTc interval to any clinically relevant extent. 12.3 Pharmacokinetics The pharmacokinetics of nirmatrelvir/ritonavir were similar in healthy subjects and in subjects with mild-to-moderate COVID-19.
Indications
- 1 INDICATIONS AND USAGE 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. PAXLOVID which includes nirmatrelvir, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (M pro : also referred to as 3CL pro or nsp5 protease) inhibitor, and ritonavir, an HIV-1 protease inhibitor and CYP3A inhibitor, is indicated for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in adults who are at high risk for...
Common Doses
- 300 mg
- 150 mg
- 100 mg
- 60 mL
Dosage
2 DOSAGE AND ADMINISTRATION 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. ( 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. ( 2.
Black Box Warning
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, or fatal events [see Contraindications (4) , Warnings and Precautions (5.1) , and Drug Interactions (7) ]. • Prior to prescribing PAXLOVID: 1) Review all medications taken by the patient to assess potential drug-drug interactions with a strong CYP3A inhibitor like PAXLOVID and 2) Determine if concomitant medications require a dose adjustment, interruption, and/or...
Contraindications
- 4 CONTRAINDICATIONS PAXLOVID is contraindicated in patients with a history of clinically significant hypersensitivity reactions [e.g., toxic epidermal necrolysis (TEN) or Stevens-Johnson syndrome] to its active ingredients (nirmatrelvir or ritonavir) or any other components of the product. 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...
Side Effects
- 6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: • Hypersensitivity reactions [see Warnings and Precautions (5.2) ] Most common adverse reactions (incidence ≥1% and greater incidence than in the placebo group) are dysgeusia and diarrhea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc. at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.
Interactions
- 7 DRUG INTERACTIONS Co-administration of PAXLOVID can alter the plasma concentrations of other drugs and other drugs may alter the plasma concentrations of PAXLOVID. Consider the potential for drug interactions prior to and during PAXLOVID therapy and review concomitant medications during PAXLOVID therapy. ( 4 , 5.1 , 7 , 12.3 ) 7.1 Potential for PAXLOVID to Affect Other Drugs PAXLOVID (nirmatrelvir co-packaged with ritonavir) is a strong inhibitor of CYP3A, and an inhibitor of CYP2D6, P-gp and OATP1B1.