Which of the following constitute extralabel use of an approved drug?

• A. Drug A is given SQ to Daisy the dairy goat and is labeled for use in bovines but not for use in caprines.
• B. Drug A is used to treat a bacterial urinary tract infection in Fluffy the cat, but the drug label only states that Drug A is to be used in cats to treat skin infections caused by susceptible strains of Pasteurella multocida.
• C. The drug label says to administer Drug A IM every 8 hours, but Bob works 12-hour shifts, so he administers a dose-and-a-half worth of Drug A IM every 12 hours instead.
• D. The package insert for Drug A says to give a dog of Buster the dog's weight one capsule every 12 hours for up to seven days, but Buster doesn't seem 100% back to normal after seven days, so the veterinarian advises the owner to continue giving Drug A every 12 hours for another five days.

Answer: (D)

Extralabel use means using an approved drug in a way not specified on its label, including changes to species, indication, dose, route, frequency, or duration. The scenario where a dog is directed to take one capsule every 12 hours for seven days, but the veterinarian advises continuing for an additional five days, clearly goes beyond the duration approved on the label. Extending therapy past the labeled seven-day course is outside what the label authorizes, so it constitutes extralabel use. The other situations also involve deviations from the label (species, indication, or dosing schedule), but the explicit extension of the treatment period above the labeled duration is the clearest example of extralabel use.