Primovir and Paxista are used to treat coronavirus disease 2019 (COVID-19 infection) caused by the SARS-CoV-2 virus in adults and children 12 years of age and older who weigh at least 88 pounds (40 kg) and are at risk of severe disease that could result in hospitalization or death. Nirmatrelvir belongs to the antiviral drug class. It works by preventing the virus from spreading throughout the body. Ritonavir belongs to a class of drugs known as "pharmacokinetic boosters." It works by boosting the quantity of nirmatrelvir available in the body, allowing the treatment to be more effective.
Nirmatrelvir and ritonavir are available as tablets to be taken orally. Nirmatrelvir and ritonavir must be taken concurrently for the medication to be effective. It is usually taken twice a day, with or without food, for five days. Nirmatrelvir and ritonavir should be taken at the same times each day. Follow the instructions on your prescription label exactly, and ask your doctor or pharmacist to explain any parts you don't understand. Nirmatrelvir and ritonavir should be taken exactly as prescribed. Do not take more or less of it or take it more frequently than your doctor has prescribed.