CYP3A4 and COVID-19: Remdesivir is an IV administered antiviral and one of the first agents to show a benefit by reducing the time to clinical recovery in COVID-19.50 Remdesivir is a minor substrate for several metabolic and transport pathways, including plasma and tissue esterases, CYP enzymes (CYP3A4, CYP2D6, and CYP2C8), and transporters (OATP1B1 and P-gp).