The use of drugs for unlabeled indications.

A chart review of 500 drug uses during a three-month period in a family practice clinic showed that 46 (9.2%) were for indications not included in the Food and Drug Administration-approved labeling. Dipyridamole was the drug most frequently and consistently prescribed for unlabeled indications. On no occasion did the chart show that patients were informed that a drug was being prescribed for an unlabeled indication. Unlabeled indications most frequently encountered in the chart review were also frequently mistaken by family practice residents and faculty responding to a questionnaire as being included in FDA-approved labeling. The indications as listed in the manufacturers' literature (eg, package insert, Physician's Desk Reference) often do not reflect how drugs are used in clinical practice.