[NMusers] Transit Compartment Model for PK with Multiple Doses

All, Has anyone ever used a transit compartment model in NONMEM for PK with multiple doses. We are looking to use ~25 transit compartments (and thus ~25 DiffEqs in the $DES block). This seems easier for multiple doses, compared to the mathematical solution detailed in Rada Savic's 2004 PAGE

[NMusers] modeling data from Cases an controls

Dear Group: I have posed this question to a different list serve as well so apologize in advance if it is a duplicate message for some of you. I have sparse data (2-3 levels /patient) for a drug used in demographically similar patients with the same disease state but the disease in one group