Perform an NCA based on a NONMEM-style dataset

Usage

nca(
  data = NULL,
  dose = 100,
  tau = 24,
  method = c("log_linear", "log_log", "linear"),
  scale = list(auc = 1, conc = 1),
  dv_min = 0.001,
  t_inf = NULL,
  fit_samples = NULL,
  weights = NULL,
  extend = TRUE,
  has_baseline = TRUE,
  route = c("iv", "oral", "im", "sc")
)

Arguments

data: data.frame with time and dv columns
dose: dose amount
tau: dosing frequency, default is 24.
method: linear, log_linear (default), or log_log
scale: list with scaling for auc and concentration (conc)
dv_min: minimum concentrations, lower observations will be set to this value
t_inf: infusion time, defaults to 0
fit_samples: vector of sample indexes used in fit to calculate elimination rate, e.g. c(3,4,5). If not specified (default), it will evaluate which of the last n samples shows the largest adjusted R^2 when log-transformed data is fitted using linear regression, and use those samples in the estimation of the elimination rate.
weights: vector of weights to be used in linear regression (same size as specified concentration data), or function with concentration as argument.
extend: perform an 'extended' NCA, i.e. for the calculation of the AUCs, back-extend to the expected true Cmax to also include that area.
has_baseline: does the included data include a baseline? If FALSE, baseline is set to zero.
route: administration route, iv (intravenous, default), oral, sc (sub-cutaneous), or im (intra-muscular).

Value

Returns a list of three lists:

pk

Lists pk parameters.

kel: elimination constant
t_12: half-life
v: distribution volume
cl: clearance

descriptive

Lists exposure parameters.

cav_t: the average concentration between the first observation and the last observation without extrapolating to tau
cav_tau: the average concentration from 0 to tau
cmin: the extrapolated concentration at time = tau
c_max_true: only available if extend = TRUE, the extrapolated peak concentration
c_max: only available if extend = FALSE, the observed maximum concentration
auc_inf: the extrapolated AUC as time goes to infinity
auc_24: the extrapolated AUC after 24 hours, provided no further doses are administered
auc_tau: the extrapolated AUC at the end of the dosing interval
auc_t: the AUC at the time of the last observation

settings

Lists dosing information.

dose: dose quantity
tau: dosing interval

Examples

data <- data.frame(time = c(0, 2, 4, 6, 8, 12, 16),
                   dv   = c(0, 10, 14, 11, 9, 5, 1.5))
nca(data, t_inf = 2)
#>               value
#> kel          0.1807
#> t_12         3.8358
#> v            4.1763
#> cl           0.7547
#> tmax         4.0000
#> cav_t        8.2119
#> cav_tau      5.7390
#> c_min        0.3534
#> c_max_true  20.0949
#> auc_inf    139.6910
#> auc_24     137.7354
#> auc_tau    137.7354
#> auc_t      131.3902
#> auc_pre     14.0000