A package insert (formally prescribing information in the United States; in Europe, Patient information leaflet for human medicines or Package Leaflet for veterinary medicines) is a document provided along with a prescription or over-the-counter medication to provide additional information about that drug.
In the United States, the Food and Drug Administration (FDA) determines the requirements for patient package inserts. Other national or international organizations that regulate medical information include the European Medicines Agency (EMA), and the Japanese Ministry of Health, Labour, and Welfare (MHLW). Other country-specific agencies, especially in the case of EU (European Union) countries and candidates, plus countries of South America and many in Asia and the Far East, rely heavily on the work of these three primary regulators. Unless otherwise stated, all information in this article refers to patient package inserts in the United States.
In the United States, the FDA will occasionally issue revisions to previously approved package inserts, in much the same way as an auto manufacturer will issue recalls upon discovering a problem with a certain car. The list of 1997 drug labelling changes can be found on the FDA's website, here.
The first patient package insert required by the FDA was in 1968, mandating that isoproterenol inhalation medication must contain a short warning that excessive use could cause breathing difficulties. The second patient package insert required by the FDA was in 1970, mandating that combined oral contraceptive pills must contain information for the patient about specific risks and benefits.)
Package inserts follow a standard format for every medication and include the same types of information. Different manufacturers may have different titles for their sections, however, to make them easier for the average person to read and comprehend—for example, instead of "Contraindications" the section may be headed, "Who should not take this medication?"