makeNCA

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mscheetz
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makeNCA

Post by mscheetz » Mon Sep 14, 2015 8:49 am

Dear Michael and all,

Sorry for stacking up queries, I know that you are prepping for a meeting. I wanted to share some hurdles that I ran into using makeNCA.

1. I have not been able to get makeNCA to calculate AUCs from time 0 to time XX when there is >1 dose within the time period. It seems that it can only calculate the first concentration time curve. Is there a way to expand this so that you can calculate AUCs from multiple doses (e.g. AUC0-24H for TID dosing to sum the AUC from 0-24 hours for all three doses)?

From the help file:
"auc
Area under the time-observation curve, using the trapezoidal approximation, from time 0 until the second dose, or if only one dose, until the last observation"

Thus, it appears that this is by design... but can another AUC be added such that it gives the AUC for the specified time period?


2. makeNCA also does not appear to like it when we modify the doses within the same time period. For instance, if 50 mg was given for the first dose and 51 mg was given for the second dose (BID dosing), it will not calculate. I get this error:
"Subject 42 does not have the same doses before all concentrations that were superimposed; shorten the time interval."

3. Is it possible to add a Cminimum calculation after the first dose?


Currently, we are pulling data from post.xx$time, post.xx$pred ... if there were autocalculations from makeNCA, that would be great!


Thanks again for a wonderful software tool.
Marc

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mneely
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Re: makeNCA

Post by mneely » Mon Sep 28, 2015 4:51 pm

Hi Marc,

Thanks for your suggestions. Yes, I know that makeNCA is not right yet. It is extraordinarily complex to figure out the right data points to use for subjects with irregular doses, dose intervals, etc. I frankly would welcome some help here. I wonder if anyone in your group would be interested in tackling the function?

mscheetz
Posts: 14
Joined: Fri Mar 23, 2012 12:40 pm

Re: makeNCA

Post by mscheetz » Fri Oct 23, 2015 7:00 am

Hi Michael,

We would love to help. My knowledge of the inner-workings of R is relatively limited. Maybe we can schedule a call with some of your programmers, and we can see where we are able to help.

Thanks again for all that your group does with Pmetrics!

Cheers,
Marc

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mneely
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Re: makeNCA

Post by mneely » Mon Nov 02, 2015 5:36 am

Sounds good. Let's make that happen.

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