The Pharmacokinetics Project Is Getting Underway

Roughly half of people with hemophilia receive smaller doses than necessary, while the other 50% receive unnecessarily high ones. The test results will help adjust doses and use the same overall consumption of therapeutic products much more efficiently.

The test of survival of the administered factor in the body very precisely determines its clearance curve and the duration of its effect. This helps determine the exact timing and amount of factor to be administered so that each person can find out when they are at their best, when the level starts to drop. This is especially important when a sporting activity or other risky activity is expected.

From all this it follows that this is primarily an aid for those who enjoy the benefits of prophylaxis - that is, the preventive administration of clotting factors. Reams of paper have been written about its medical and economic benefits at every age, and no one doubts it. Unfortunately, it is not very widespread in our country, but a certain percentage of hemophilia patients do undergo it. We warmly recommend that all members request it at their centers. The arguments about significant financial costs are no longer entirely valid today.

However, pharmacokinetics is also relevant for "on-demand" treatment. It can precisely determine to what level the factor will rise after drug administration and how long it will maintain the required level in the body.

But let us return to pharmacokinetics - what does it mean in practice? First of all, the factor level needs to be raised to a starting point, which means administering approximately 3,000 IU. Then the declining level is gradually measured at specific intervals, and based on the time curve and a developed mathematical model, it is possible to determine each person's individual response. This response is virtually unchanging and inherent to the very nature of each individual - current fitness or other influences play an absolutely minimal role.

The development of the complex mathematical model was commissioned by the Institute of Hematology and Blood Transfusion, and its use is simple - values are simply entered into an Excel table and the result is read off.

A similar project for pediatric patients has been running for a year. The Brno center has already tested all pediatric patients with severe hemophilia this way, and for some, treatment has already been adjusted based on pharmacokinetic results, sometimes including a change of product. The situation with children is additionally different in that their pharmacokinetics can change during growth and development. It therefore sometimes needs to be performed repeatedly. Pediatric patients in Brno then receive a report containing not only the results of their own pharmacokinetics but also their interpretation (for example, during which time interval "risky activities" can be performed, when it is time for calm work and normal household activities, and when one really needs to be careful). Everything is always explained in detail to both parents and young hemophilia patients at a level they can understand. Pharmacokinetic testing can also be arranged at Motol University Hospital. Other pediatric facilities are gradually joining as well.

So visit your center and ask its specialists to arrange a test at the Prague institute or at another facility that deals with pharmacokinetics. Your center should definitely know about it - it cannot be done without their cooperation. They also need to provide you with those 3,000 units (for adults). This is a cost that is absolutely minimal compared to the effect achieved.