Background In the post-marketing setting, spontaneous reporting is an important tool for the surveillance of Adverse Drug Reactions (ADRs). However, underreporting is a major limitation of a pharmacovigilance system. Several studies showed that ADRs may cause hospitalisation resulting in an increase in hospital stays and costs.

Purpose To gather information on the extent and frequency of ADRs at Careggi University Hospital, and to identify unreported ADRs to the Pharmacovigilance Office, using the hospital discharge records.

Materials and Methods We analysed the hospital discharge records from January 2011 to June 2012. In particular, we considered those records with a Drug Related Group (DRG) classification related to allergic reactions, poisoning and toxic effects of drugs (DRGs from 447 to 451). We included in our analysis records referring to poisoning, according to the new pharmacovigilance legislation in force from July 2012. Our research gave us information about the number of suspected reactions, but it didn’t provide specific information on the patients and the seriousness of the reaction.

Results We obtained 346 records related to the DRGs selected: 101 (29%) ADRs and Testing Oral Exposure to Drugs, 91 (27%) poisoning, 20 (6%) drug abuse, 7 (2%) reactions to foods and 97 (28%) unspecified events. It was possible to identify the drug involved in only 51 records: antibiotics, NSAIDs, chemotherapy agents, local anaesthetics, opioids and immunoglobulin were the agents mainly reported. Only 2 cases had been reported to the Pharmacovigilance Office and entered in the Italian National Pharmacovigilance Database.

Conclusions Our survey shows a mismatch between the ADRs documented in the hospital discharge records and those actually reported to the hospital’s Pharmacovigilance Office, highlighting the problem of under-reporting. The data could be useful for implementing measures to raise awareness among health care professionals and to spread the culture of drug safety.

No conflict of interest.