Paxista is a combination antiviral medication containing nirmatrelvir and ritonavir. It is primarily used to treat COVID-19 in adults and adolescents at high risk of developing severe disease. Nirmatrelvir inhibits the virus itself, while ritonavir boosts nirmatrelvir’s effect by slowing its breakdown in the body.

Mechanism of Action:

• Nirmatrelvir: Blocks the main protease (Mpro) enzyme of SARS-CoV-2, preventing the virus from replicating in human cells.

• Ritonavir: Inhibits the liver enzyme CYP3A4, which slows down the metabolism of nirmatrelvir, ensuring higher levels of nirmatrelvir in the blood for a longer time.

  Uses 

  • Treatment of mild to moderate COVID-19 in adults and children (12 years and older, weighing at least 40 kg) who are at high risk of progressing to severe COVID-19.

  • Helps reduce hospitalization and death from COVID-19.

    Adverse Effects:

    Common side effects include:

    • Altered taste (metallic or bitter taste)

    • Diarrhea

    • High blood pressure

    • Muscle aches

    • Headache