Adverse reactions induced by NSAIDs and antibacterials: analysis of spontaneous reports from the Sicilian regional database.

OBJECTIVES: To (i) evaluate the suspected adverse drug reactions (ADRs) related to NSAIDs and antibacterials that were reported to Sicilian local health officers by healthcare professionals; and (ii) to detect new or serious potential signals of alarm related to these two widely used drug categories. METHODS: We selected all the spontaneous reports of ADRs sent between January 1998 and June 2004 and analysed those attributed to NSAIDs and systemic antibacterials, applying proportional reporting ratio (PRR) methodology. PRRs >2, chi(2) >4 and >3 ADRs were regarded as signals. RESULTS: During the period considered, 1585 reports of ADRs were received overall (42.6\% serious), with an annual reporting rate of approximately 49.1 reports per million inhabitants on average; 351 referred to systemic antibacterials, and 179 to NSAIDs. There were 174 (49.6\%) reports of serious ADRs associated with antimicrobials and 108 (60.3\%) associated with NSAIDs. Disproportionality was observed, in particular for anaphylactic shock induced by ceftriaxone (all reports were associated with off-label use of the drug), photosensitivity reaction induced by lomefloxacin (administered in the summer), hepatitis induced by nimesulide (three cases leading to liver transplantation) and vasculitis induced by nimesulide. CONCLUSION: Our analysis highlighted several signals of alarm deserving further investigation or measures to influence prescribing. This study underlines the value of a regional centre in identifying local factors (such as prescribing patterns) that may increase the prevalence of serious ADRs.