# Modeling TMDD in Phoenix **URL:** \ **Category:** Modelling and Simulation\ **Created:** [February 9, 2017, 5:59pm UTC](https://forum.certara.com/t/modeling-tmdd-in-phoenix/3130 "2017-02-09T17:59:31Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Mukesh\_Kumar](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mukesh\_Kumar](https://forum.certara.com/u/Mukesh_Kumar)\ **Post date:** [February 9, 2017, 5:59pm UTC](https://forum.certara.com/t/modeling-tmdd-in-phoenix/3130/1 "2017-02-09T17:59:31Z")
Hi all, I’ve been having a few issues modeling drugs that suffer from rapid target mediated disposition. Essentially w/severe TMDD we see a 1-2 log drop in first 24-48 hours, then multi-day recovery of serum drug levels and negligible elimination, followed by a first order elimination around day(s) 7-10. Has anybody successfully modeled these triphasic elimination scenarios in Phoenix? Any tips on the model/compartment structure? I want to avoid going to Matlab for, well, lazy reasons. Below is an example using hEPO: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3157300/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3157300/) Thanks in advance! ![Screen Shot 2017-02-09 at 9.56.46 AM.jpg](https://us1.discourse-cdn.com/certara/original/2X/2/2ec287098f4c92863e7e6c047061317abf9bcaad.jpeg) ---
**Author:** ![Samer\_Mouksassi](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Samer\_Mouksassi](https://forum.certara.com/u/Samer_Mouksassi)\ **Post date:** [February 23, 2017, 3:04pm UTC](https://forum.certara.com/t/modeling-tmdd-in-phoenix/3130/2 "2017-02-23T15:04:44Z")
Hi did you try to code it into PML and give it a shot there is no way to predict that a minimization engine would file without trying. I am not sure what minimization algorithms are available in Matlab you can always tweak some of the solver tolerance parameter to get to what you want