Spontaneous reporting of adverse drug reactions: a ten years\' contribution of the activity of the Regional Pharmacovigilance Unit of Central Portugal for drug safety knowledge

D Mendes1, C Alves2,3, C Fontes-Ribeiro1,4, F Batel-Marques1,2. 1AIBILI, Health Technology Assessment (HTA) Centre, 3000-548 Coimbra, Portugal, 2University of Coimbra, School of Pharmacy, 3000-548 COimbra, Portugal, 3University of Beira Interior, Health Sciences Research Centre, 6201-506 Covilhã, Portugal, 4University of Coimbra, School of Medicine, 3000-548 Coimbra, Portugal

Background: Pharmacovigilance is aimed at detecting, assessing and preventing adverse drug reactions (ADR). Spontaneous reporting is a method of pharmacovigilance used by health professionals to report suspected ADR. Reporting suspected ADR contributes to better benefit/risk ratio evaluations of drugs and for patient safety.

Objectives: This study aims to characterize the suspected ADR reported to the Regional Pharmacovigilance Unit of Central Portugal (UFC), to document the contribution of reports of ADR by health professionals to pharmacovigilance in Portugal, and to identify the new knowledge produced by the activity of the UFC.

Methods: Spontaneous reports (SR) of ADR received in the UFC between January 2001 and August 2011 that met the primary inclusion criteria (patient, suspected drug, adverse event and health professional identified) and the secondary inclusion criteria (information on ADRs’ previous description, ADRs’ severity and causality assessment) were included. An expert panel (comprised by experts in clinical pharmacology, clinical pharmacy, pharmacy and medicine) assessed ADRs’ previous description, severity and causality. Causality was assessed using the global introspection method. Severity was assessed according to World Health Organization (WHO) criteria. Previous description of an ADR was assessed by consulting the Summary of Product Characteristics. Suspected drugs were classified in categories according to the Portuguese Drug and Therapeutics Bulletin. ADR were classified according to the MedDRA dictionary. Data processing was performed using the Statistical Package for Social Sciences (version 17.0; SPSS Inc., Chicago, IL, USA).

Results: The UFC received 1846 SR of ADR between 2001 and August 2011. Of these, 999 met the inclusion criteria. We identified 149 (14.9%) unknown ADR and 428 (42.8%) serious ADR. Seventy (7.0%) ADR were simultaneously unknown and serious and 41 (4.1%) simultaneously unknown, serious, and certain or probable. Ambulatory care was the origin of the majority of SR of ADR (n=427; 42.7%), followed by hospital (n=320; 32.0%) and community pharmacy (n=239; 23.9%). Physicians reported 577 (57.8%) ADR, of which 340 (34.0%) were reported by family physicians. Pharmacists reported 354 (35.4%) ADR and nurses 66 (6.6%).

Conclusions: Unknown ADR (149; 14.9%), unknown and serious ADR (70; 7.0%) and unknown serious certain or probable ADR (41; 4.1%) received by the UFC show that spontaneous reporting of suspected ADR is of great value in increasing knowledge about the safety profiles of drugs.