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kram ☆ India, 2010-10-05 17:25 (5319 d 01:36 ago) Posting: # 5998 Views: 6,350 |
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Dear All, If I want to estimate Cmin and Tmin for single dose study then how can I get done with WinNonlin 5.3?? If I use steady state procedure by providing, Dose=dose strength Time of last dose=0 Tau=24 (since our last sampling time point is 24) then obtained Cmin and Tmin are useful or not ?? Kindly suggest me the solution. Thanks in advance. Ram Edit: Category and subject line changed. [Helmut] |
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Helmut ★★★   Vienna, Austria, 2010-10-05 17:39 (5319 d 01:22 ago) @ kram Posting: # 6000 Views: 5,966 |
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Dear Ram, I'm not sure whether I do understand your question. In a single dose study Cmin/tmin should be (by definition) <LLOQ/0. If not - your analytical method may be flawed, or the washout was too short (pre-dose concentrations in higher periods). Yes, you can use the coding you gave in WinNonlin. ❝ then obtained Cmin and Tmin are useful or not ?? Can you give us an example (profile of one subject and WinNonlin's results)? — Dif-tor heh smusma 🖖🏼 Довге життя Україна! ![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png) Helmut Schütz ![[image]](https://static.bebac.at/img/CC by.png) The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
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kram ☆ India, 2010-10-06 14:02 (5318 d 04:59 ago) @ Helmut Posting: # 6007 Views: 5,563 |
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Dear HS, Thanks for your prompt reply, Actually this question related to serum analysis. and Sponsor interested, to check if any change from baseline values and treatment values (decrease in values or not)? They ask me to calculate maximum decrease in serum concentration (somewhere middle of sampling hour this value comes) and time of max. decrease. I don't have data but following are expected data values. e.g. for subj 1
time point: 0 2 4 6 8 10 12 14 16 18 20Kindly go through it, waiting for your valuable comment. Ram |
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Helmut ★★★ Vienna, Austria, 2010-10-06 15:34 (5318 d 03:27 ago) @ kram Posting: # 6009 Views: 5,701 |
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Dear Ram! ❝ Actually this question related to serum analysis. and Sponsor interested, to check if any change from baseline values and treatment values (decrease in values or not)? ❝ They ask me to calculate maximum decrease in serum concentration (somewhere middle of sampling hour this value comes) and time of max. decrease. I'm still not sure whether I do understand the problem. You are expecting that administering an endogenous compound to decrease serum levels? Which drug are you talking about? Or are you administering drug A (which you can't measure) and looking on it's effect on endogenous compound B? ❝ I don't have data but following are expected data values. ❝ e.g. for subj 1 ❝ ❝ Are these endogenous levels (a 'normal' profile) or already ones expecting after administration? I would suggest to treat the data in WinNonlin as pharmacodynamic rather than pharmacokinetic ones (NCA Model 220 instead of NCA Models 200-212). Just give it a try. Celebrating login #3000 today. — Dif-tor heh smusma 🖖🏼 Довге життя Україна! Helmut Schütz The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
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SDavis ★★ UK, 2010-10-08 21:05 (5315 d 21:56 ago) @ kram Posting: # 6020 Views: 5,564 |
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Helmut gives good advice re NCA 220 i.e. the PD model. You may want to also use transform (or multi-transform) to calculate change from baseline. Also for your endogenous compound you may want to check if the 'baseline' is constant or needs to be modelled with some diurnal or other variation. Best regards, Simon. Get tips and discuss Pharsight products with other users; www.pharsight.com/extranet ___________________________________ Forthcoming meetings and training -http://www.pharsight.com/training; Transitioning to Phoenix v6.1: 2 Nov 2010 Bristol, UK (prior to PKUK). Population analysis with Phoenix v6.1 NLME : 2-4 Nov 2010, Paris, France. Introduction to Phoenix v6.1: 8-10 Dec 2010, Paris, France. |
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kram ☆ India, 2010-10-13 13:46 (5311 d 05:14 ago) @ SDavis Posting: # 6051 Views: 5,885 |
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Dear HS and Simon, Many many thanks for your suggestions, I will go through it and let you know about results. thanks again, Thanks and Regards, Ram |
Ing. Helmut Schütz