Plasma and Urine data

Dear NMusers, I am working on a dataset with drug concentration data in both plasma and urine. I found most of the control streams dealing with urine data previously posted here were based on user-defined differential equations. My question is whether a normal ADVAN1 control stream and dataset can be changed to allow urine data to be used. If so, what has to be change in the control stream and the dataset? I’d sincerely appreciate it, if somebody can share with me a sample control stream to simultaneously fit the plasma and urine data. Kind regards, Norman Zhou