Extralabel

Extralabel refers to the use of a drug or medical product in a manner not specified on the product’s label. In veterinary medicine, extralabel use, often called off-label use, involves treating animals with a drug for a species, indication, dosage, route of administration, or duration that is not included on the label. It is governed in the United States by the Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA), which allows veterinarians to authorize extralabel use when no approved treatment exists and it is in the animal’s best interest, provided certain conditions are met. These conditions typically include a valid veterinarian–client–patient relationship, use only when necessary and supported by professional judgment, avoidance of unsafe practices, and thorough recordkeeping. For food-producing animals, withdrawal times and residue considerations are emphasized to protect public health.

Outside veterinary medicine, extralabel use mirrors the broader concept of off-label use in humans, where a drug is prescribed for indications, populations, or routes not specified on the labeling. In human medicine, off-label use is common and may be supported by clinical evidence or guidelines, but it carries a higher degree of uncertainty regarding safety and efficacy and often requires informed consent.

Regulatory landscapes vary by country. In the United States, AMDUCA governs veterinary extralabel use, while in the European Union and other regions, national guidelines align with general pharmacovigilance and prescribing norms. Regulators monitor safety, and authorities can restrict or withdraw approvals if risks are identified. The term extralabel highlights the balance between clinical need and patient safety, emphasizing practitioner responsibility to base decisions on evidence, minimize risks, and maintain transparent records.