A survey of spontaneous reporting of adverse drug reactions in 10 years of activity in a pharmacovigilance centre in Portugal

Abstract

Reporting of adverse drug reactions (ADRs) may differ between countries. In a retrospective descriptive study we analysed the potential causative drugs and clinical situations related to spontaneously reported ADRs over 10 years to a regional pharmacovigilance centre in Portugal. We collected 3165 cases (36% of all national reports) of ADRs reported by doctors (54%), pharmacists (31%), and nurses (15%), 56% of which were classified as serious, 22% as unexpected and 13% as both serious and unexpected. According to World Health Organization causality criteria of ADRs related to drugs, 67% where probable, 20% possible, 7% conditional, 6% certain and 1% unclassifiable or unlikely. There was a predominance of females (66%, P < 0.005) both for total and serious ADRs. Physicians, while working in hospitals, reported more (68%) and more serious ADRs (75%) than those working in primary care (29%). Pharmacists working outside hospitals reported more (90%) than those working in hospitals. Drugs more frequently associated with ADRs were antibiotics (22%), followed by vaccines (16%), drugs acting on the nervous system (15%), non-steroidal anti-inflammatory drugs (14%) and those working on the cardiovascular system (11%). The most common systems, organs or disorders affected by ADRs were skin manifestations (21%), followed by general disorders (20%), gastrointestinal/hepatobiliary disorders (15%), nervous system disorders (11%) and immune system disorders (6%). Our study shows a general commitment of Portuguese health professionals to ADR reporting with a clear predominance of serious rather than non-serious ADRs. This study may help to improve the recognition of the general aspects of ADRs occurring in Portugal.