[A retrospective pharmacovigilance analysis: could decreased reporting of suspected adverse reactions generate future safety concerns?] / Un'analisi retrospettiva di farmacovigilanza: la diminuzione della segnalazione di sospette reazioni avverse potrebbe generare futuri problemi di sicurezza?

BACKGROUND: The collection and management of spontaneous reports of suspected adverse drug reactions represents a passive pharmacovigilance method for post-marketing drug safety surveillance, as it is a practical and rapid way to detect a potential warning sign. We performed an in-depth retrospective analysis of suspected adverse reaction reports in the National Pharmacovigilance Network (RNF) for the first eight months of 2019 (pre-pandemic period), 2020 (global pandemic covid-19 onset), 2021 (first post-pandemic period due to vaccine phase). METHODS: The reports of suspected adverse drug reactions were extrapolated from the National Network of Pharmacovigilance. Data from Italy, the Campania Region, and the Local Health Unit Naples 3 South were compared. A retrospective qualitative analysis of demographics data, clinical status, suspected drugs, adverse drug reactions (ADRs) description and its degree of seriousness were collected. RESULTS: We observed 1071 ADRs, of which 281 were serious; of these, 39 led to hospitalization, 779 were not serious, and 2 caused death. In the pre-pandemic period, chemotherapy drugs most frequently induced ADRs. The year 2020, in the midst of the covid-19 pandemic, saw a clear reduction in the number of drug reports, compared to 2019 and 2021, both at national and regional level, and at ASL Napoli 3 Sud. A reduction in 2020 that ranges from -40.75% to -72.56% at the national and regional level, respectively; reaching as much as -88.13% at the local level in the health authority under analysis. In 2021, on the other hand, there is a clear increase in the number of reports, which numerically exceed even those in 2019 by +194.71% in Italy, +15.25% in the Campania Region, and +90.68% in the Local Health Unit Naples 3 South. CONCLUSIONS: The covid-19 pandemic has affected the trend in the number of reports of suspected adverse drug reactions. This is for several reasons: first, frontline exposed health care workers have been able to devote less time to pharmacovigilance activities to cope with the health emergency, second, since the start of the covid-19 vaccination campaign, health care workers have been more focused on reporting suspected adverse reactions to vaccines. Clinicians should beware of these adverse effects and monitor early warning signs carefully.