Pharmacokinetic (PK) has improved our knowledge about the most appropriate dosing and timing of administration of FVIII/FIX concentrates in patients with Haemophilia. However, although several studies have recently addressed the relevance of PK of clotting factors, usual practice is still mostly based on empiric approaches since individual PK estimation is difficult to obtain unless the patient is formally enrolled in a study. In fact, several plasma samples collected over several hours and/or days are required to establish a half-life curve confidently and this may be a relevant problem, especially in children. Recently however population PKs has emerged as an important tool to overcome this drawback. Targeted prophylaxis could take advantage of knowing the individual response to factor concentrate administration. On the clinical ground, age and body weight (BW) are roughly used to guide dosing because usually in vivo recovery is lower and clearance is faster in children than in adults.
Keywords: Factor VIII, Factor IX, Haemophilia A, Haemophilia B, Pharmacokinetics.