What does it mean when a drug is used in a manner not specified in the FDA's package insert?

When a drug is used in a manner not specified in the FDA's package insert, it is referred to as "off-label use." This term denotes the practice of prescribing medications for purposes outside of the approved indications, dosages, or patient populations as outlined in the official labeling. Off-label use is common in medical practice, especially when healthcare providers believe that a certain medication may benefit a patient based on their clinical judgment and available evidence, even if the specific use has not been formally approved by regulatory authorities.

This practice can be particularly relevant in veterinary medicine, where certain drugs may be applied to species or conditions not explicitly detailed in package inserts. It is important for veterinarians and technicians to be aware of off-label use guidelines and to look for scientific support or empirical evidence backing their clinical decisions when utilizing drugs in such a manner.

The other options do not accurately describe this practice; "experimental use" typically refers to drugs still in clinical trials rather than approved for market but used in research settings. "Unauthorized use" implies that the drug is being used without any legal or regulatory approval, which does not apply to off-label uses with supported evidence. "Adverse use" is not a recognized term in this context and does not appropriately describe the concept of