Graphical calculation of clearance and volume of distribution (IV route)

Estimates clearance (CL), volume of distribution (Vd), terminal slope (lambdaz), and extrapolated concentration at time zero (C0exp) from intravenous pharmacokinetic data using graphical methods.

Usage

graphcal_iv(dat, dose = 1, ...)

Arguments

dat

A data frame containing TIME (time after dosing) and DV (observed concentration).

dose

Administered dose amount. Defaults to 1.

...

Additional arguments passed to force_find_lambdaz().

Value

A list containing graphical estimates of CL, Vd, lambda_z, and C0exp.

Details

Terminal slope (lambdaz) is estimated using force_find_lambdaz(), which applies an automated phase selection strategy with fallback regression when required.

See also

force_find_lambdaz

Author

Zhonghui Huang

Examples

dat <- data.frame(TIME = c(0.5, 1, 2, 4, 6, 8, 10),
                  DV = c(12, 8, 5, 3, 2, 1.5, 1))
graphcal_iv(dat, dose = 100)
#> $cl
#> [1] 2.951299
#> 
#> $vd
#> [1] 16.47151
#> 
#> $slope
#> [1] -0.1791759
#> 
#> $C0exp
#> [1] 6.071088
#> 
#> $method
#> [1] "find_best_lambdaz"
#> 
#> $slopefit
#> 
#> Call:
#> lm(formula = log(conc[subset]) ~ time[subset])
#> 
#> Coefficients:
#>  (Intercept)  time[subset]  
#>       1.8035       -0.1792  
#> 
#> 
#> $time.spent
#> [1] 0.003
#>