Preventability of adverse effects of analgesics: analysis of spontaneous reports.

Abstract

The aims of this study were to determine the patterns of analgesic adverse drug reactions (ADRs) and to assess their preventability and contributing factors. This is a retrospective, descriptive study conducted on ADRs of analgesics and other drugs indicated as analgesics, spontaneously reported to the Bordeaux pharmacovigilance center from January 2011 to June 2012. The 141 cases selected for the analysis included 16 cases of medication errors (11.3%) and 15 addiction cases (10.6%). In total, 214 ADRs were registered, for which 173 analgesic medicines were suspected. The most frequent ADRs reported were nervous system disorders (26.6%), psychiatric disorders (15.0%), and skin and subcutaneous tissue disorders (12.1%). Tramadol alone or in combination (17.3%), followed by morphine (15%), fentanyl (9.8%), and paracetamol (8.7%) were the most frequently involved analgesics. More than half of the cases (54.6%) were serious and led to hospitalization or prolonged hospitalization. Preventability was determined for 134 cases (95%): 51.5% were considered as preventable, 26.1% not preventable, and 22.4% not assessable. The main contributing factors for the preventable cases included negligence of recommendations for analgesic use and failure to consider patients' risk factors when prescribing. A significant number of analgesic ADRs could be prevented, and being aware of their contributing factors promotes efficient analgesia with minimum risks to the patients.