The pharmaceutical industry focuses its postmarketing safety resources primarily on spontaneous reporting systems. This is partly due to the emphasis by national regulatory authorities on such systems and their data. While there is definite value in spontaneous reporting schemes as early warning systems, they by themselves cannot confirm, validate, and quantify risks.

Without the ability to measure adverse reaction risks that are common as well as those that are rare, events considered clinically serious and those not thought to be serious, true benefit-to-risk determinations cannot be made at either the public health or individual patient care levels. The recent Council for International Organizations of Medical Sciences report, or CIOMS IV , expertly highlights these issues facing regulatory authorities.

Drug product labeling is the legal basis for most product advertising and information communicated to the health practitioner. However, prescription drug labeling is of increasingly diminished value once a drug is in clinical use, since safety data are no longer systematically collected. Risks associated with drug use in clinical practice are largely undetermined, so the professionals who prescribe pharmacotherapy may have no firm basis on which to make safety decisions.