World Health Organization Geneva
Modern medicines have changed the way in which diseases are managed and controlled. However, despite all their benefits, evidence continues to mount that adverse reactions to medicines are a common, yet often preventable, cause of illness, disability and even death. In some countries, adverse drug reactions (ADRs) rank among the top 10 leading causes of mortality. Aside from the intrinsic dangers associated with the products them-selves, individual patients may exhibit particular and unpredictable sensitivities to certain medicines. In addition, if more than one medicine is prescribed, there is always a risk of negative interactions. The selection and use of the best and safest medicine(s) for a given individual out of the many choices avail-able thus requires considerable skill on behalf of the prescribing practitioner.
In order to prevent or reduce harm to patients and thus improve public health, mechanisms for evaluating and monitoring the safety of medicines in clinical use are vital. In practice this means having in place a well-organized pharmacovigilance system. Pharmacovigilance - an umbrella term used to describe the processes for monitoring and evaluating ADRs - is a key component of effective drug regulation systems, clinical practice and public health programmes.