This is primarily done when an FDA-approved product is not available, an existing drug contains properties that cause allergies in the patient, or an existing drug needs to be administered by a different means, i.e., orally instead of intravenously.
Compounded drugs can play an especially important role in the veterinary world.
Consequently, there is a need for pharmacists to specialize or customize a drug for a particular animal. The individual pharmacist determines the precise amounts of the ingredients that go into the compounded product, so a compound product created by one pharmacist may likely vary from one created by another. These compounded products do not require FDA approval, and while the pharmacies are overseen and regulated, the compound is neither analyzed nor checked for quality or efficacy, Dr. Kollias-Baker says. Because these compounds do not undergo efficacy trials and studies, as do FDA-approved drugs, they usually are cheaper to purchase. Occasionally, a veterinarian requests a compounded drug when an existing product for treating a disease in that species already exists, usually because the client wants a cheaper alternative to the FDA-approved product.