Fitting Compartment Models Using PROC NLMIXED

There is a new article on SAS's website "Fitting Compartment Models Using PROC NLMIXED". It is nice to know that SAS Proc NLMIXED can be used for fitting the compartment model in pharmacokinetic (PK) analyses.

Usually, for PK analyses, the non-compartment model will be used - i.e., Cmax, Tmax,... are based on the observed values and AUC is calculated using the trapezoid rule. I would say that for more than 90% of times, the non-compartment model will be good enough for the PK analyses.

However, in some situations, the non-compartment model or non-compartment analysis (NCA) will not be adequate. One-compartment model with first-order elimination and two-compartment model with first-order distribution and elimination processes may be more appropriate.

For PK analyses using NCA, the most commonly used software is Phoenix WinNonLin that was developed by Pharsight and now owned by Certara. For PK analyses based on compartment models, the most commonly used software is NONMEM that was developed by UCSF and now managed by ICON plc.