FAQ

This page summarizes the frequent questions about PKanalix.

Resolution and display

  • OpenGL technology impact on remote access: the PKanalix interface uses OpenGL technology. Unfortunately, remote access using direct rendering is not compatible with OpenGL, as the OpenGL application sends instructions directly to the local hardware bypassing the target X server. As a consequence, PKanalix cannot be used with X11 forwarding. Instead, an indirect rendering should be used, where the remote application sends instructions to the X server which transfers them to the graphics card. It is possible to do that with ssh application, but it requires a dedicated configuration depending on the machine and the operating system. Other applications such as VNC or Remina can also be used for an indirect rendering.
  • If the graphical user interface appears with too high or too low resolution, follow these steps:
    • open PKanalix
    • load any project from the demos
    • in the menu, go to Settings > Preferences and disable the “High dpi scaling” in the Options.
    • close PKanalix
    • restart PKanalix

Regulatory

  • Are NCA and CA analyses done with PKanalix accepted by the regulatory agencies like the FDA and EMA?  Yes.
  • How to cite PKanalix? Please reference it as here
    PKanalix version 2019R1. Antony, France: Lixoft SAS, 2019.
    http://lixoft.com/products/PKanalix/

Running PKanalix

  • On what operating systems does PKanalix run? PKanalix runs on Windows, Linux and MacOS platform.
  • Is it possible to run PKanalix in command line? It is possible to run PKanalix from the R command line. A full R -api providing the full flexibility on running and modifying PKanalix projects is described here

Input data

  • Does PKanalix support sparse data? No.
  • Does PKanalix support drug-effect or PD models? No.
  • What type of data can PKanalix handle? Extravascular, intravascular infusion, intravascular bolus for single-dose or steady-state plasma concentration and single-dose urine data can be used. See here.
  • Can I give the concentration data and dosing data as separate files? No.
  • Can I give the dosing information directly via the interface? No.
  • Can I have BLQ data? Yes, see here.
  • Can I define units? No.
  • Can I define variables such as “Sort” and “Carry”? Yes, check here.
  • It is possible to define several dosing routes within a single data set? Yes, check the ADMINISTRATION ID column.
  • Can I use dose normalization to scale the dose by a factor? No, this must be done before using PKanalix.

Settings (options)

  • How do I indicate the type of model/data? Extravascular versus intravascular is set in the Settings window. Single versus steady-state and infusion versus bolus are imputed based on the data set column-types.
  • Can I exclude data with insufficient data? The “Acceptance criteria” settings allow the user to define acceptance thresholds. In the output tables, each individual is flagged according those criteria. The flags can be used to filter the results outside PKanalix.
  • Can I set the data as being sparse? No, sparse data calculations are not supported.
  • Which options are available for the lambda_z calculation? Points to be included in the lambda_z calculation can be defined using the adjusted R2 criteria (called best fit in Winonlin), the R2 criteria, a time range or a number of points. In addition, the a specific range per individual can be defined, as well as points to include or exclude. Check the lambda_z options here and here.
  • Can I define several partial areas? No.
  • Can I save settings as template for future projects? Not for settings. However the user can set the data set headers that should be recognized automatically in “Settings > Preferences”.
  • Do you have a “slope selector”? Yes, check here for information on the “Check lambda_z“.
  • Can I define a therapeutic response range? No.
  • Can I set a user-defined weighting for the lambda_z? No. But most common options are available as a setting.
  • Can I disable the calculation of lambda_z (curve stripping in Winnonlin)? Set to general rule to a time interval that does not contain any point. For a single individual, select a single point. This will lead to a failure of the lambda_z calculation and parameters relying on lambda_z will not be calculated.

Output results

  • Can I change the name of the parameters? No. However the output files contain both PKanalix names and CDISC names.
  • Can I export the result table? The result tables are automatically saved as text files in the result folder. In addition, result tables can be copy-pasted to Excel or Word using the copy button on the top right of the tables.
  • Can I generate a report? No. But the result tables can be copy-pasted to Excel or Word using the copy button on the top right of the tables. Plots can be exported as images using in the menu “Export > Export plots” or by clicking on save button at the top of each plot.
  • Can I choose which parameters to show in the result table and to export to the result folder file? No. All parameters are exported. The user can filter the table outside PKanalix afterwards.
  • Are the calculation rules the same as in Winonlin? Yes.
  • Can I define myself the result folder? By default, the result folder corresponds to the project name. However, you can define it by yourself. See here to see how to define it on the user interface.

Results

  • What result files are generated by PKanalix?
  • Can I replot the plots using another plotting software? Yes, if you go to the menu Export and click on “Export charts data”, all the data needed to reproduce the plots are stored in text files.
  • When I open a project, my results are not loaded (message “Results have not been loaded due to an old inconsistent project”). Why? When loading a project, PKanalix checks that the project (i.e all the information saved in the .pkx file) being loaded and the project that has been used to generate the results are the same. If not, the error message is shown. In that case the results will not be loaded because they are inconsistent with the loaded project.