You can provide any number of samples and we will do our best to produce an estimate. However, we recommend:


Factor VIII


  1. Best Option: 4 HRS, 24 and 48 HRS
  2. Alternative: 8 HRS, 30 HRS
  3. Alternative: 24 HRS

Note: all times are indicative, e.g. 24 can be anytime between 18 and 30 hours.



                         Add an additional sampling point at 60-84 HRS.


Factor IX


  1. Best Option: Any Time on day 2 and 3
  2. Alternative: Two samples on any of day 2 or 3 -optimally, 4 or more hours apart


                                          Day 1 starts at 0 and end at 24

                                          Day 2 starts at 24 and end at 48

                                          Day 3 starts at 48 and end at 72

                                          There is no day 0. That is for surgery only.

 EHL Factor IX


Add an additional sampling point at 4 – 5 days.



Please note: 

There is no need to perform a wash out, however, we strongly recommend you provide a pre-infusion measurement.


You can request a PK using data obtained after different infusions using the merge function provided these criteria are met:

  • Within an 18-month timespan
  • Same total dose (+/- 10%)
  • Patient weight (+/- 5kg) and height (+/- 10%) are stable