. 2022 Sep 20;396(1):73–82. doi: 10.1007/s00210-022-02292-6

Table 1.

Ordinary differential equations that best describe the pharmacokinetic model for remdesivir and its two metabolites GS‐774277 and GS‐441524

C_{c RDV} = A_{(RDV Central compartment)}/Vd_{c RDV}
C_{p RDV} = A_{(RDV Peripheral compartment)}/Vd_{p RDV}
C_{c GS‐774277} = A_{(GS‐774277 Central compartment)}/Vd_{c GS‐774277}
C_{p GS‐774277} = A_{(GS‐774277 Peripheral compartment)}/Vd_{p GS‐774277}
C_{c GS‐441524} = A_{(GS‐441524 Central compartment)}/Vd_{c G GS‐441524}
C_{p GS‐441524} = A_{(GS‐441524 Peripheral compartment)}/Vd_{p GS‐441524}
$\frac{DA}{DT}$ _{(RDV Central compartment)} = (Input) + (Q_RDV × C_{p RDV}) − (Q_RDV × C_{c RDV}) − (CL_RDV × C_{c RDV}) − (CLm_{c GS‐774277} × C_{c RDV})
$\frac{DA}{DT}$ _{(RDV Peripheral compartment)} = (Q_RDV × C_{c RDV}) − (Q_RDV × C_{p RDV}) − (CLm_{p GS‐774277} × C_{p RDV})
$\frac{DA}{DT}$ _{(GS‐774277 Central compartment)} = (CLm_{c GS‐774277} × C_{c RDV}) + (Q_GS‐774277 × C_{p GS‐774277}) − (Q_GS‐774277 × C_{c GS‐774277}) − CL_GS‐774277 × C_{c GS‐774277}) − (CLm_{c GS‐441524} × C_{c GS‐774277})
$\frac{DA}{DT}$ _{(GS‐774277 Peripheral compartment)} = (Q_GS‐774277 × C_{c GS‐774277}) + (CLm_{p GS‐774277} × C_{p RDV}) − (Q_GS‐774277 × C_{p GS‐774277})
$\frac{DA}{DT}$ _{(GS‐441524 Central compartment)} = (CLm_{c GS‐441524} × C_{c GS‐774277}) + (Q_GS‐441524 × C_{p GS‐441524}) − (CL_GS‐441524 × C_{c GS‐441524}) − (Q_GS‐441524 × C_{c GS‐441524})
$\frac{DA}{DT}$ _{(GS‐441524 Peripheral compartment)} = (Q_GS‐441524 × C_{c GS‐441524}) − (Q_GS‐441524 × C_{p GS‐441524})

Ordinary differential equation pharmacokinetic behavior model was developed based on mean concentration data obtained from phase I clinical trials, where remdesivir was administered in different doses as single-dose 2-h intravenous infusion in healthy subjects. DA/DT represents the change rate of drug amount in the respective compartment. C_c concentration in the central compartment; C_p concentration in the peripheral compartment; A the amount of a substance at a time; CL total body clearance; Vd_c and Vd_p the volume of distribution for central and peripheral compartments, respectively; Q inter-compartmental clearance; CLm formation clearance of metabolites