Pharmacovigilance in the pharmaceutical industry.

Abstract

Pharmacovigilance has been defined as the process of identifying and responding to drug safety issues [1] and has grown considerably as a discipline over the past 10 to 15 years. An educational survey in 1994 revealed that more than 320 people currently worked in company pharmacovigilance functions in the UK alone [2]. Pharmaceutical companies are international, hence the number of staff working in this field within the industry, particularly in other European countries and the USA, is far greater. A major pharmaceutical company such as Astra has over 100 permanent, experienced staff in pharmacovigilance within its research and development organisation in Sweden and the UK and a similar number in local operating companies worldwide. This development has been driven by an increased recognition of the role of pharmacovigilance, the investigation and marketing of a wider range of diverse medicinal products and more stringent and detailed regulatory requirements. The number of individual reports of possible adverse drug reactions (ADRs) can be considerable, for key marketed products often more than 1000 case reports a year are received worldwide from health care professionals and other sources. The aims of pharmacovigilance within the industry are essentially the same as those of regulatory agencies; that is to protect patients from unnecessary harm by identifying previously unrecognised drug hazards, elucidating pre-disposing factors, refuting false safety signals and quantifying risk in relation to benefit. Although the perspectives of companies and the regulatory agencies may be different they now work more and more closely together and share information. However, central pharmacovigilance units in major pharmaceutical companies in many instances are far better resourced and have much greater ‘in-house’ expertise on the safety of their particular products. Scientific characteristics Although now seen as a discipline in its own right, pharmacovigilance is related to a number of scientific disciplines, the most important being clinical medicine, clinical and pre-clinical pharmacology, immunology, toxicology and epidemiology. The identification and analysis of the safety characteristics of medicines falls into two distinct stages. During the first stage, before marketing, the main methodology is experimental with clinical trials comparing the new treatment to placebo or existing alternative treatments. After introduction of a new medicine into general use, the main safety methodology is observational, i.e. uses data from observation of patients treated in clinical practice rather than from experimental situations. In general, the experimental data are of much higher quality than the observational, with better control of confounding factors. The challenge in pharmacovigilance, therefore, is to analyse and draw well-founded conclusions from observational data collected after marketing. In addition, data from observational epidemiological studies are playing an increasingly important role.