PP130—Evaluation of the influence of cytocrome P450 oxidoreductase (POR) in the stable dose of acenocoumarol

e56 Volume 35 Number 8S therapeutic range (2.0–3.0 + 0.2), encompassing a period of at least 2 weeks and with a maximum difference between the mean daily dosages of 25%. The association between genotypes and time-toachieve stability was evaluated using survival analysis techniques. A Cox proportional hazard model was used to assess the relative risk of achieving a first period of stability in the follow-up period. Results: Results showed that time-to-achieve treatment stability with acenocoumarol is decreased significantly for carriers of ABCB1 c.3435TT genotype and extended in wild-type and heterozygous subjects (HR, 2.94 [IC 1.22–7.09]). Similarly, carriers of ABCB1 c.2677GT or TT genotypes reached more rapidly stability than wild-type subjects (HR, 2.15 [IC, 1.07–4.98] and HR, 3.00 [IC, 1.08–8.36], respectively). The other tested polymorphisms (CYP2C9, CYP2C19 and VKORC1) had no influence on the time-to-achievestability. Conclusion: Our results suggest for the first time that time-to-achieve stability with acenocoumarol is shorter to reach in carriers of ABCB1 c.3435TT and carriers of ABCB1 c.2677GT/TT combined. Further studies are required to assess whether the identification of ABCB1 genotypes before treatment with acenocoumarol may be useful for a safer and rapid anticoagulation stabilization. Disclosure of Interest: None declared.