5 replies to this topic

[Hellot]

Hi, is there a way to process a NCA (at once) of repeated doses (extravascular) profiles? we can set several dosing times but i understand the software manage the analysis of the last dose conc-time profile. If not, each dose-data set should be analysed separately?

Thank you for your help, Edouard.

[Simon Davis]

Edouard, it depends no how you've structured your data but it may be as simple as adding Day to your sort variables.

 

ie. tp give profiles;

Subject 1, Day 1

Subject 1, Day 7

Subject 2, Day 1

Subject 2, Day 7

etc.

 

If you post your project/data file then we can advise better.

 

Simon

[Hellot]

Edouard, it depends no how you've structured your data but it may be as simple as adding Day to your sort variables.

 

ie. tp give profiles;

Subject 1, Day 1

Subject 1, Day 7

Subject 2, Day 1

Subject 2, Day 7

etc.

 

If you post your project/data file then we can advise better.

 

Simon

OK thank you. Quite simple indeed. I don't have yet the reflex to use this sort function. In that case, the file use for the NCA cannot be used for plotting the full conc-time profile of each subject (one plot with all doses and PK) as i guess you need to duplicate the row with the last conc following a given dose (the last conc of Dose N is also the predose Dose N+1 but if you sort with Dose for NCA, then time of dosing of Dose N+1 cannot be the time of Dose N). Ed

[Simon Davis]

..In that case, the file use for the NCA cannot be used for plotting the full conc-time profile of each subject (one plot with all doses and PK) as i guess you need to duplicate the row with the last conc following a given dose (the last conc of Dose N is also the predose Dose N+1 but if you sort with Dose for NCA, then time of dosing of Dose N+1 cannot be the time of Dose N). Ed

Again without seeing your actual data file and your reporting protocol needs it's not possible to say for sure, but remember that in Phoenix you can indeed create extra columns using e.g. the Data Wizard to hold a continuous time from first dose as well as time relative to last dose.

  if you need to create extra rows i.e. so that Day 2, 0h also exists as Day 1, 24h then this is a data management issue that has existed at least 20 years, again you can do it in Phoenix, however I would really recommend that your data supplier takes responsibility to create this record for you, (same sample has two 'PK' identities), with some flag to indicate the sample record is duplicated if required.

 

  Simon.

[Helmut Schütz]

Hi Simon,

 

… if you need to create extra rows i.e. so that Day 2, 0h also exists as Day 1, 24h then this is a data management issue that has existed at least 20 years,…

 

Absolutely. No big deal.

 

…however I would really recommend that your data supplier takes responsibility to create this record for you, (same sample has two 'PK' identities), with some flag to indicate the sample record is duplicated if required.

 

IMHO, not realistic. There is just one unique sample which was measured – so likely only one concentration will be reported. It depends on the coding the bioanalytical CRO is using (as the last of dose N or first of dose N+1). Having GLP in mind, the request for “duplicating” results will give the bioanalyst an anaphylactic shock. IMHO, it’s rather the job of the data management / pharmacokineticist.

Edited by Helmut Schütz, 29 June 2015 - 03:37 PM.

[Simon Davis]

IMHO, it’s rather the job of the data management / pharmacokineticist.

I would concur and furthermore I think it should be done by Data Management since they are 'managing the data' hence I orginally said 'data supplier' not lab ;0)
 

On the plus side you can do it in Phoenix quite easily if they aren't so co-operative!

  Simon