gms | German Medical Science

Background: 5-10 % of all hospital admissions in Europe are caused by adverse drug reactions (ADR), many of them are considered to be preventable. Oral anticoagulants and antiplatelets range among the most frequently ADR-associated drugs and have a high potential for particularly serious ADR. Dosing recommendations based on genotypes for CYP2C9, VKORC1 and CYP2C19 have been developed. However, their benefit in clinical routine cannot be evaluated without taking other risk factors such as high age, multimorbidity, impaired renal function and polypharmacy into account. Until now, there has been no pragmatic randomized controlled trial to investigate the effect of a comprehensive individualized risk assessment of an anticoagulant/antithrombotic therapy on the incidence of ADR and their pharmacoeconomic consequences in a realistic outpatient setting.

Materials and Methods: The IDrug-Study is a two-arm, randomized, controlled, multicenter trial. Objective is to evaluate the effect of an individualized risk assessment leaflet on the incidence of adverse drug reactions compared to a standardized leaflet in a cohort of 960 elderly multimorbid outpatients (≥ 60 years) on oral anticoagulants or antiplatelets. Eligible patients are randomized to receive either a standardized leaflet containing general information about the HAS BLED- and CHA2DS2-VASc-Score, drug-drug-interactions, age, renal function and pharmacogenetic factors or a personalized leaflet addressing the same subjects but taking the patients individual clinical data into account. After a follow up period of nine months the occurrence of thromboembolic / bleeding events or deaths as well as other adverse drug reactions, hospital admissions, resulting costs and the patients’ health related quality of life will be compared in both groups.

Results: Until now, 84 patients from 17 medical practices have been included in the study and randomized for receiving either standardized or individualized risk assessment. Currently, more medical practices are being recruited and initiated to participate in the study.

Conclusion: Individualized approaches including the patient’s clinical and genetic findings might have the potential to reduce ADR especially in cohorts at high risk. After finishing the study we will verify if an individualized risk assessment can improve patient safety and be beneficial for the patient himself as well as the health care system. The results of this study might be a first step towards evidence-based policies for individualized risk information for patients.