Abstract 11598: Is Therapeutic Drug Monitoring of Direct Anticoagulants Really Unnecessary?

• Published in: Circulation (New York, N.Y.) N.Y.), 2015-11, Vol.132 (Suppl_3 Suppl 3), p.A11598-A11598
• Main Authors: Baldin, Bernadette, Warembourg, Marion, Bardy, Guillaume, Startari, Loïc, Rocher, Fanny, Spreux, Anne, Lavrut, Thibaud, Drici, Milou-Daniel
• Format: Article
• Language: English
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/circ.132.suppl_3.11598

Introductionno routine monitoring is deemed necessary with direct oral anticoagulants dabigatran (D) and rivaroxaban(R). Yet, their misuse may lead to inefficacy or increased risk of bleeding.Hypothesisdue to the prevalence of elderly patients in our medical center, the pharmacology department was asked to measure R and D plasma concentrations. Therefore we aimed not only to check their prescription adequacy but also to evaluate whether bleeding or thrombosis adverse events were associated with drug concentrations clearly outside of their expected “normal” range.MethodsPatients receiving R or D for either AFib, deep venous thrombosis or its prevention were included and had blood samples drawn for drug measurements, by HPLC-tandem mass spectrometry. Adequacy of the patient prescription was checked by pharmacists according D & R respective SmPCs. A robust and conservative method was applied to evaluate anticoagulant concentrations D & R concentrations were blindly deemed “normal” when within the [IC]95 limits (peak and trough, relative to the dose) observed in the respective RE-LY and Rocket-AF pivotal studies, as compared to “out of range” when outside of these limits.Results287 consecutive patients from our center had their concentration of R (n=219 76%) or D (n = 68 24%) measured. The inadequacy of the prescriptions was 31.4% alltogether. Seventy patients presented with bleeding (n = 48, 17%) or thrombosis (n = 22, 8%), that either led to their admission in emergency, or occurred in the hospital wards. Bleedings and thrombosis were significantly associated with out-of-range concentrations (p