Monitoring risk: post marketing surveillance and signal detection.

The primary goal of postmarketing surveillance is to provide information for risk assessment of a drug. Drugs affecting the central nervous system form a unique group of products for surveillance because they are often misused, abused, and diverted. These medications include opioid analgesics, stimulants, sedative-hypnotics, muscle relaxants, anticonvulsants and other drug classes. Their adverse events are difficult to monitor because the perpetrator often attempts to conceal the misuse, abuse and diversion of the product. A postmarketing surveillance system for prescription drugs of abuse in the U.S. should include product specific information that is accurate, immediately available, geographically specific and includes all areas of the country. Most producers of branded opioid analgesic products have created systems that measure abuse from multiple vantage points: criminal justice, treatment professionals, susceptible patient populations and acute health events. In the past, the U.S. government has not established similar requirements for the same products produced by generic manufacturers. However, the Food and Drug Administration Amendments Act of 2007 includes generic opioid analgesic products by requiring that all products containing potent opioid drugs perform rigorous surveillance and risk management. While general risk management guidance has been developed by FDA, more specific analyses and guidance are needed to improve surveillance methodology for drugs which are misused, abused, diverted.