Appraising the post-marketing safety of medicines: A description of national and international pharmacovigilance with a focus on medicines used in chronic pain

Clinicians play a key role in appraising the safety of medicines after marketing. A wide variety of adverse reactions and novel interactions may occur in individual patients. Formal reporting by prescribers and evaluation of their observations to allow timely communication of risk back to the end users is vital. Many countries have regional or national pharmacovigilance centres which contribute to the World Health Organization (WHO) Global Individual Case Safety Report (ICSR) database, VigiBase. We describe the role of pharmacovigilance in detecting and evaluating emerging evidence of adverse drug reactions, i.e. “signals” using the New Zealand Pharmacovigilance Centre as an example. The benefits to individual patient safety through a medical warning system are of particular relevance to anaesthetic practice. Effective and holistic pharmacovigilance relies on voluntary reporting systems for all therapeutic products, prescription or cohort event monitoring of selected medicines and vaccines, and specific monitoring of medication error. Ongoing development of computational methods for data-mining in the voluntary reporting databases for signal detection and the application of these methods to electronic longitudinal health care databases such as general practice records in order to detect, confirm or refute, and characterise signals of adverse drug reactions are also described.