[A retrospective pharmacovigilance analysis: could decreased reporting of suspected adverse reactions generate future...

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).

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.

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.

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.