Research into the best, safest uses of a medicine does not end once a drug is approved by the Food and Drug Administration (FDA). Making sure that medicines are safe and effective for their intended use is an on-going process that is closely monitored by manufactures, prescribing physicians and the FDA. The following elements provide a brief overview of the reasons for and process used in the post-market monitoring of medicines.

1. Not all of the safety issues can be determined through the development phase of a drug.
2. Rare adverse drug reactions are often not detected during research and development because though the number of volunteer patients in clinical testing can go up to 10,000, the overall patient population is frequently much larger.
3. To address this challenge, companies maintain large dedicated divisions that study safety issues when a drug is marketed.
4. Serious and life-threatening adverse drug reactions must be reported to the Food and Drug Administration within 15 days.
5. During the first three years the product is on the market, companies file quarterly reports with FDA outlining all new safety issues that have come to the company’s attention. Annual reports are filed after that for as long as a company markets a drug.
6. The FDA has an independent Office of Drug Safety for dealing with reported side effects not found during the drug approval process. The number of safety officers is being doubled, from 100 to 206, as 106 new officers are added over the next couple of years.
7. Nevertheless, both the FDA and companies are constantly looking at ways to improve adverse reaction detection and reporting. FDA recently created a new drug safety board within the agency.