In the United States, the regulations of the Food and Drug Administration (FDA) permit physicians to prescribe approved medications for other than their intended indications. This practice is known as off-label use.

The legal, prescribed use of a drug in a manner different from that described on the Food and Drug Administration (FDA)-approved drug label. Off-label use can include using a drug for a different disease or medical condition or giving a drug at a different dose or via a different route of administration than approved by FDA. See Related Term(s): Fo [..]

Physician-approved use of a drug for uses other than those stated on its label Opiate

Use of a therapeutic agent to treat conditions for which the relevant regulatory authority (e.g. the Therapeutic Goods Administration) has not registered its use.