Cases of drug-induced Torsade de Pointes: a review of Belgian cases in the EudraVigilance database

OBJECTIVES: Post-marketing surveillance is very important, especially for rare adverse drug reactions like QTc-prolongation and Torsade de Pointes (TdP). The objective of this study was to investigate the characteristics of Belgian cases of drug-related TdP reported in the EudraVigilance database. METHODS: The EudraVigilance database was searched for Belgian post-marketing cases of TdP reported between December 2001-April 2015. These cases were identified with MedDRA preferred terms. Duplicate reports were excluded. Each included case report was reviewed to collect data about age, gender, seriousness, suspected drug, concomitant drugs, causality, and other known risk factors for QTc-prolongation. RESULTS: Between 2001 and 2015, only 31 cases coded as TdP were identified; 16 cases were also coded as 'prolonged QT' and 2 patients died. In total, 21 suspected drugs were implicated and most of them (N = 11) were part of list 1 of CredibleMeds. The most common suspected drugs were citalopram (N = 4) and amiodarone (N = 3). In 18 cases, a pharmacodynamic drug-drug interaction with risk of QTc-prolongation was present. Most patients (N = 25) had ≥2 other risk factors for QTc-prolongation. CONCLUSION: Over 15 years, only a low number of Belgian cases of TdP were identified in the EudraVigilance database. In most case reports, multiple risk factors for QTc-prolongation could be detected. This illustrates that there is a clear underreporting of QTc-prolongation and TdP in Belgium. Initiatives are needed to improve the awareness and knowledge of health care professionals regarding the risk of QTc-prolongation and TdP, both to prevent cases of TdP and to stimulate the reporting of these cases.