Immune support and respiratory infection care
Not recommended
Ritonavir is an HIV protease inhibitor used in combination with nirmatrelvir (Paxlovid) for treatment of mild-to-moderate COVID-19 in patients at high risk of progression ( EUA 2021, NIH COVID-19 Guidelines 2024). Stand-alone ritonavir is occasionally prescribed for immunity or COVID-19 without the full Paxlovid regimen. Without combination with nirmatrelvir or other antiretrovirals, ritonavir does not work in COVID-19; international clinical guidelines do not include such use. Ritonavir is a strong CYP3A4 inhibitor with severe drug interactions (statins, , direct oral anticoagulants, some immunosuppressants are contraindicated). If ritonavir was prescribed without the full Paxlovid regimen or antiretroviral therapy, consider seeking a second opinion.