PAXLOVID™ (nirmatrelvir tablets; ritonavir tablets)

PAXLOVID™ (nirmatrelvir tablets; ritonavir tablets) 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.

Product Expiration Date

The product expiration date is stated on the product packaging, both on the carton and on the individual blister cards.

Mechanism of Action

Nirmatrelvir is a peptidomimetic inhibitor of the SARS-CoV-2 main protease (Mpro), also referred to as 3C-like protease (3CLpro) or nonstructural protein 5 (nsp5) protease. Inhibition of SARS-CoV-2 Mpro renders it incapable of processing the viral polyproteins pp1a and pp1ab, preventing viral replication. Nirmatrelvir inhibited the activity of recombinant SARS-CoV-2 Mpro in a biochemical assay with a Ki value of 3.1 nM and an IC50 value of 19.2 nM. Nirmatrelvir was found to bind directly to the SARS-CoV-2 Mpro active site by X-ray crystallography.

Ritonavir is an HIV-1 protease inhibitor but is not active against SARS-CoV-2 Mpro. Ritonavir inhibits the CYP3A-mediated metabolism of nirmatrelvir, resulting in increased plasma concentrations of nirmatrelvir.

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Dosing Information

Patients should take PAXLOVID twice daily for 5 consecutive days.

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Drug Interactions

Consult appropriate references for comprehensive information.

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How to verify your tablets are authentic

PAXLOVID must be prescribed by a licensed healthcare provider and supplied by a government approved pharmacy or medical facility.

Authentic PAXLOVID, from Pfizer Inc., will include the Pfizer name on the label and will be packaged in 5 aluminum push-through blister cards. Individual doses are not for sale. PAXLOVID will be packaged in a rectangular carton. The carton has a colorless, glossy coating that contains a repeated pattern of the Pfizer name and logo all over, and these repeating features are seen in a contrasting matte finish.

PAXLOVID consists of tablets for a 5-day oral treatment regimen, with morning and evening doses.

Pfizer is committed to patient safety and ensuring that people have accurate information about the investigational drug PAXLOVID, including how it is accessed and administered. We are actively monitoring for fraudulent offers of illegitimate PAXLOVID to protect patients from products that might be dangerous and lead to serious and life-threatening harm.

If you suspect the product you have received may be counterfeit, visit www.pfizer.com.hk/en/connect-with-us

Reference: Paxlovid (Nirmatrelvir, Ritonavir) Prescribing Information. Pfizer Corporation Hong Kong Limited Version May 2023