Off-label use of drugs and other agents can be very anxiety-producing for doctors because of concerns related to potential malpractice suits. Until quite recently, once an agent was approved it could only be marketed/promoted by the pharmaceutical company for the use or disease indication (intended indication) and in the manner described on the approved written instructions and information or drug label. Uses of the drug to treat other conditions or uses in manners not described on the label are called “off-label” uses. Sometimes, off-label uses are called “unapproved uses” or even “illegal uses”. Using the words “illegal” and “unapproved” is most often intended to convey a characterization which is inappropriate but it does occur, especially when condemning certain medical practices or as part of a malpractice suit attempt. Because the FDA-approved written instructions and information (“label”) are based on information available from the studies submitted in order to obtain marketing approval, the label often ends up being quite narrow compared to a drug’s actual use as determined in practice and by studies not used for FDA approval or label changes. For example, after approval and broad availability and use of a drug, new indications are found based on serendipitous observations and empiric evidence. There is a widening of the criteria for use even for patients who have the labeled indication, because, for example, the diagnostic criteria for the labeled indication are loosened, or combinations of the drug with other agents become the standard of care.