Nirmatrelvir/ritonavir

Nirmatrelvir/ritonavir, sold under the brand name Paxlovid, is a co-packaged medication used as a treatment for COVID‑19. It contains the antiviral medications nirmatrelvir and ritonavir and was developed by Pfizer. Both components are protease inhibitors: nirmatrelvir inhibits SARS-CoV-2 main protease, while ritonavir inhibits HIV-1 protease, and is additionally a strong CYP3A inhibitor. It is taken by mouth.

In unvaccinated high-risk patients with COVID-19, nirmatrelvir/ritonavir can reduce the risk of hospitalization or death by 88% if taken within five days of symptom onset. Patients who take nirmatrelvir/ritonavir also test negative for COVID-19 about two and a half days earlier than patients who do not take the drug. Side effects of nirmatrelvir/ritonavir include changes in sense of taste (dysgeusia), diarrhea, high blood pressure (hypertension), and muscle pain (myalgia).

In December 2021, nirmatrelvir/ritonavir was granted emergency use authorization (EUA) by the United States Food and Drug Administration (FDA) for the treatment of COVID‑19. It was approved in the United Kingdom later that month, and in the European Union and Canada in January 2022. In May 2023, it was approved in the United States for the treatment of mild-to-moderate COVID‑19 in adults who are at high risk for progression to severe COVID‑19, including hospitalization or death. The FDA considers it to be a first-in-class medication.

On 29 January, 2024, FDA revised the EUA status of Paxlovid and announced that Paxlovid manufactured and labeled in accordance with the EUA (EUA-labeled Paxlovid) currently in U.S. distribution will remain authorized for use through the labeled or extended expiration date, as applicable, or through March 8, 2024, whichever is earlier.