Under-reporting of adverse drug reactions: A problem that also involves medicines subject to additional monitoring; preliminary data from a single-centre experience on novel oral anticoagulants

BACKGROUND:Spontaneous reporting system is the most widely used method by pharmacovigilance centers. Its "voluntary nature" represents the main cause of adverse drug reaction (ADR) under-reporting phenomena. The aim of this study was to point out the issue of ADR under-reporting from doctors, particularly serious ADRs and adverse reactions caused by medicinal products subject to additional monitoring, such as novel oral anticoagulants (NOACs). METHODS:Only serious ADRs were analyzed, defined as death, life-threatening ADR, hospitalization (initial or prolonged), disability (significant or permanent), congenital anomaly. Firstly, we analyzed suspected adverse reaction alerts to NOACs submitted to the Area Vasta 2 (ASUR Marche) pharmacovigilance center, from June 16, 2013 to January 14, 2017. Then, we examined alerts coming from all over Italy and from the Marche Region in the same time period. Secondly, the analysis was focused on the Senigallia hospital (where we had an easy access to the medical records archive); patients who experienced an ADR in that time period were identified retrospectively and an alert was submitted. Thirdly, from January 15, 2017 to March 15, 2017, suspected ADR alerts were submitted prospectively. RESULTS:Phase 1: in 43 months, 1625 alerts were submitted from all over Italy, 18 from the Marche Region (one of them from the Senigallia hospital). Phase 2: 8 suspected serious ADRs were collected retrospectively (2 fatal and 3 life-threatening). Phase 3: in only 2 months, 7 serious ADRs were observed prospectively (2 fatal and 1 life-threatening). CONCLUSIONS:Our study shows that among doctors the under-reporting phenomenon is remarkable and it also involves medicinal products subject to additional monitoring and serious ADRs, including deaths.