Mechanism of action of Nirmatrelvir/Ritonavir combination (Nirmatrelvir/Ritonavir)

Nematrelvir/Ritonavir tablet combination Paxlovid (Nirmatrelvir/Ritonavir) includes severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) major protease (Mpro: also known as 3CLpro or nsp5 protease) inhibitor nematvir and HIV-1 protease inhibitor and CYP3A inhibitor ritonavir. By inhibiting Mpro, nematvir prevents the virus from processing the polyprotein precursors required for its replication. Ritonavir can be used as a pharmacokinetic enhancer to reduce CYP3A-mediated metabolism of nematvir to increase the plasma concentration of nematvir sufficient to reach the target therapeutic range.