Prevalence and Causes of Preventable and Serious Adverse Drug Reactions Related to the Use of Oral Anticoagulants

Study Overview
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Brief Summary
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The purpose of this study is to investigate the preventability of serious adverse drug reactions (ADRs) related to the use of direct oral anticoagulants (DOACs). The investigators also aim at identifying the underlying causes of these preventable ADRs. The endpoint measurements will be compared with a group of patients taking vitamin-K antagonists (VKAs). For this purpose, a protocol for a prospective observational study was developed. The study was approved by the Ethics Committee of the CHU UCL Namur (site Godinne) and the Cliniques Universitaires Saint-Luc. Patients admitted to the emergency department of these two teaching hospitals with a thrombotic or a bleeding event while under DOAC or VKA are included. After a comprehensive medication history, the appropriateness of prescribing is evaluated, using an adapted version of the Medication Appropriateness Index. Causality, severity and preventability of adverse events are assessed by two pharmacists and two hematologists using predefined scales. Second, for cases of serious and preventable ADRs, semi-structured interviews are performed with general practitioners to understand the underlying causes of medication errors. Based on the results, risk-minimization strategies that specifically target the problems encountered in clinical practice will be proposed.

Official Title
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Prevalence and Causes of Preventable and Serious Adverse Drug Reactions Related to the Use of Oral Anticoagulants

Conditions
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Embolism and Thrombosis, Hemorrhage

Intervention / Treatment
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* Biological: Blood samples for DOAC measurement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Admitted to the emergency department Presenting a thrombotic or a bleeding event Prescribed NOAC (rivaroxaban, dabigatran etexilate or apixaban) or VKA

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: DOAC-treated patients<br>Concerning patients taking DOACs, blood samples are drawn to evaluate DOAC plasma concentration. One EDTA tube is also drawn to extract DNA and determine the genetic profile of genes involved in the metabolism of DOACs. The aim will be to assess if genetic determinants can explain the observed interindividual variability in plasma concentrations. | Biological: Blood samples for DOAC measurement<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Preventability of adverse drug reactions according to Hallas criteria |  | Baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Appropriateness of prescribing according to the Medication Appropriateness Index |  | Baseline |