Off-label use

Off-label use is the use of pharmaceutical drugs for an unapproved indication or in an unapproved age group, dosage, or route of administration. Both prescription drugs and over-the-counter drugs (OTCs) can be used in off-label ways, although most studies of off-label use focus on prescription drugs. Off-label use is very common and generally legal unless it violates ethical guidelines or safety regulations. The ability to prescribe drugs for uses beyond the officially approved indications is commonly used to good effect by healthcare providers. For example, methotrexate is commonly used off-label because its immunomodulatory effects relieve various disorders. However, off-label use can entail health risks and differences in legal liability. Marketing of pharmaceuticals for off-label use is usually prohibited. An indication is when a drug is medically appropriate for a given condition; an approved indication is when a government drug regulatory agency formally agrees that the drug is medically appropriate for the named condition. Indications may depend not only upon the medical condition that is being treated, but also upon other factors, such as dose, the patient's age, size and sex, whether the patient is pregnant or breastfeeding, and other medical conditions. For example, aspirin is generally indicated for a headache, but it is not indicated for headaches in people with an allergic reaction to it. When the drug's manufacturer has received a marketing authorisation from the government agency, then it is allowed to promote the drug for the specific, agreed-upon approved indications in that country. All legally approved indications are listed on the drug package insert or "label". Drug manufacturers are not legally permitted to encourage the use of regulated drugs for any indications that have not been formally approved by the country's government, even if significant scientific evidence exists for that unapproved indication, or if another country's drug agency has approved that indication.