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🩺🩺 IV Infusion Steady State ​

For IV Infusion administration at steady state, the following parameters are calculated as described. The term steady state means that the rate of input and rate of elimination of the drug are equivalent; however, there is nothing in the data of a single dosing interval that can independently determine if steady state has been achieved. A user must confirm that steady state has been achieved by other methods (e.g. monitoring trough values over several dosing intervals).

Imputations ​

If the analysis dataset does not include a concentration value at the time of dose administration, a value will be imputed from the dataset. That value will be the minimum observed concentration between the time of dose administration and dose administration plus the dosing interval (Tau). The imputed concentration will be added to the dataset with a time value equal to the time of dose administration. This value is used in all parameter calculations.

If the analysis dataset does not include a concentration value at time Tau, a value will be imputed from the dataset. That value will be extrapolated from the last time point prior to Tau using the terminal elimination rate constant as described in extrapolation methods.

Parameters that do not depend on a terminal slope ​

Parameter nameParameter code in outputDescription of calculation
AUC all linearAUC_all_linSum of partial AUC values for all time points using the linear method
AUC all linear/DoseAUC_all_lin_DAUCalllinDose
AUC all linlogAUC_all_logSum of partial AUC values for all time points using the linear up log down method
AUC all linlog/DoseAUC_all_log_DAUCalllogDose
AUC last linearAUC_last_linSum of partial AUC values from time of dose administration through Tlast using the linear method
AUC last linear/DoseAUC_last_lin_DAUClastlinDose
AUC last linlogAUC_last_logSum of partial AUC values from time of dose administration through Tlast using the linear up log down method
AUC last linlog/DoseAUC_last_log_DAUClastlogDose
AUMC all linearAUMC_all_linSum of partial AUMC values for all time points using the linear methd
AUMC all linlogAUMC_all_logSum of partial AUMC values for all time points using the linear up log down methd
AUMC last linearAUMC_last_linSum of partial AUMC values from time of dose administration through Tlast using the linear methd
AUMC last linlogAUMC_last_logSum of partial AUMC values from time of dose administration through Tlast using the linear up log down methd
Last measurable concentrationClastAnalyzed concentration value greater than zero with the largest associated time value.
Maximum concentrationCmaxMaximum concentration value in the analyzed concentration column.
Cmax/DoseCmax_DCmaxDose
Minimum concentrationCminMinimum concentration value in the analyzed concentration column.
DoseDoseDose amount
Time of DoseDose_timeTime of dose administration
Duration of infusionInf_durDuration of infusion
End of infusionInf_endEnd of infusion
Infusion rateInf_rateInfusion rate
Start of infusionInf_startStart of infusion
Number of BLQ samplesN_blqTotal number of observed concentrations reported as "BLQ"
Number of missing samplesN_missTotal number of observed concentrations reported as "Missing"
Number of samplesN_sampTotal number of records in the observed concentration column. Observations that are below the limit of quantitation (BLQ) are counted, but missing observations are not counted.
SwingSwing(Cmaxβˆ’Cmin)Cmin Reported as missing if Cmin = 0.
Time of ClastTlastValue in the time column the corresponds to Clast.
Time of CmaxTmaxValue in time column that corresponds to the maximum concentration. If there are two identical values at the maximum concentration, the earliest time is reported.
Time of CminTminValue in time column that corresponds to the minimum concentration. If there are two identical values at the minimum concentration, the earliest time is reported.
End of dosing interavalend_intervalTime of the end of the dosing interval
TautauDosing interval

Parameters that depend on a terminal slope ​

Parameter nameParameter code in outputDescription of calculation
AUC Tau linearAUC_tau_linSum of partial AUC values from time of dose administration through end_interval using the linear method
AUC Tau linear/DoseAUC_tau_lin_DAUCtaulinDose
Percent extrapolated AUC Tau linearAUC_tau_lin_extrap100βˆ—[AUCtaulinβˆ’AUClastlinAUCtaulin]; otherwise 0.
AUC Tau linlogAUC_tau_logSum of partial AUC values from time of dose administration through end_interval using the linear up log down method
AUC Tau linlog/DoseAUCINFLOG_DAUCtaulogDose
Percent extrapolated AUC Tau linlogAUC_tau_log_extrap100βˆ—[AUCtaulogβˆ’AUClastlogAUCtaulog]; otherwise 0.
AUMC Tau linearAUMC_tau_linSum of partial AUMC values from time of dose administration through end_interval using the linear methd
AUMC Tau linlogAUMC_tau_logSum of partial AUMC values from time of dose administration through end_interval using the linear up log down methd
Accumulation indexAcc_index1(1βˆ’eβˆ’kelβˆ—Tau)
CLss linearCLss_linDoseAUCtaulin
CLss linlogCLss_logDoseAUCtaulog
Average concentration linearCavg_linAUCtaulinTau
Average concentration linlogCavg_logAUCtaulogTau
Trough concentrationCtauConcentration at time equal to end_interval. If an observed value is not available, logarithmic extrapolation using Clast and kel is performed. Reported as 0 if there is a BLQ value at time equal to end_interval.
Fluctuation linearFluct_lin100βˆ—(Cmaxβˆ’Cmin)Cavglin
Fluctuation linlogFluct_log100βˆ—(Cmaxβˆ’Cmin)Cavglog
Fluctuation Tau linearFluct_tau_lin100βˆ—(Cmaxβˆ’Ctau)Cavglin
Fluctuation Tau linlogFluct_tau_log100βˆ—(Cmaxβˆ’Ctau)Cavglog
MRT linearMRT_linAUMCtaulinAUCtaulin
MRT linlogMRT_logAUMCtaulogAUCtaulog
Swing with CtauSwing_Tau(Cmaxβˆ’Ctau)Ctau Reported as missing if Ctau = 0.
Vss linearVss_linMRTlinβˆ—CLlin
Vss linlogVss_logMRTlogβˆ—CLlog
Vz/F linearVz_f_linDosekelβˆ—AUCtaulin
Vz/F linlogVz_f_logDosekelβˆ—AUCtaulog
Terminal slope groupgroupGroup number for each estimated terminal slope. For each profile at least one terminal slope is calculated. All parameters that are dependent on estimation of the terminal slope are also calcualted and given the same group number.
Terminal slope interceptinterceptIntercept of linear regression.
Terminal slopekelNegative of estimated slope by linear regression of the natural log-transformed analyzed concentrations and the time of each observation.
Terminal slope adjusted r-squaredkel_adjr21βˆ’(1βˆ’kel_r2)βˆ—[kelnβˆ’1kelnβˆ’2]
Terminal slope lower time pointkel_lowSmallest time value used to calculate the terminal slope.
Number of data points in terminal slope calculationkel_nNumber of samples included in teh terminal slope calculation.
Terminal slope r-squaredkel_r2r2 value from terminal slope linear regression.
Terminal slope spankel_spankelupperβˆ’kellowkelthalf
Terminal half lifekel_thalfln(2)kel
Terminal slope upper time pointkel_upperLargest time value used to calculate the terminal slope.