2 replies to this topic

[harishkk]

Hello,

I am trying to enter infusion rate "A1Rate" to run infusion data in NLME, what is the way to enter the dose and A1 rate

 

Regards

HK

[Simon Davis]

Did you read the NLME user guide, page 18 defines these;

 

A1: The amount of drug administered intravenously.
A1 Rate: The rate of infusion for drugs administered intravenously.

Time: The relative or nominal dosing times used in a study.  <Note this is the start of the dosing .e.g. start of infusion>

 

So remembering that you will keep consistent units of time between dosing and observations, I'll assume you have time of observations in hours;

 

Imagine you have a 50mg dose delivered in 1 hour then the rate is 50mg/h

 

if you delivered the 50mg dose in just 30mins i.e. 0.5 hours then the rate is 100mg/h

 

if you delivered the 50mg dose in just 15 mins i.e. 0.25 hours then the rate is 200mg/h.

 

  If it helps think of a pump that has no timed 'stop' function (WNL classic models expect), so when you are setting the rate of delivery, you ensure that you only put the required amount of dose in the syringe so once that has been delivered dosing has finished and the pump stops.

 

  Below is an example of a 2 hour infusion.  50mg has to be delivered but the rate is only 25, therefore it will be 2 hours before all the dose has been given.

   Simon.

Attached Thumbnails

• 

Edited by Simon Davis, 22 January 2016 - 10:37 AM.

[Ana Henry]

If it helps, with path PHX029  (available at certara support for PHX 1.4) some additional functionality was added so you can enter duration of infusion instead of rate.  Here is the notification:

 

When "Infusions possible?" is checked, the tool now accepts rate OR dose and duration (QC 8261):  In Patch PHX029, this improvement has only been included at the engine level.  To use this feature, the user must go to the Model Text tab and use the User-Provided Extra Column Definition Text to specify which columns in the dataset to use for A1 and Duration.  For example, if you want to map the "dose" column to A1 and "InfTime" column to duration, you would specify the following: 

    dose(A1<-"dose", duration = "InfTime")

Note that a command-line user can also use the dose and duration by writing the statement as above.