Off-label prescribing of erythropoiesis-stimulating proteins in US hospitals

This study quantifies and describes off-label prescribing of currently marketed erythropoiesis-stimulating proteins (ESP): epoetin alfa and darbepoetin alfa. Methods: A retrospective database study examined on-label, off-label supported, and off-label unsupported ESP treatment of anemia in 464,834 inpatients. Findings: Epoetin was used in 97% of the patients studied from January 2002 to June 2004. ESPs were prescribed on-label in 48% of patients primarily for chronic kidney disease and nonmyeloid cancers. Off-label supported use was seen in 38% of patients mainly for unlabeled chronic kidney disease indications and anemia associated with critical illness. Off-label unsupported use occurred in 14% of prescriptions for cardiovascular, pulmonary, pediatrics, and other conditions. Differences in prescribing were associated with hospital, physician, patient, clinical, and drug variables. Conclusions: Off-label ESP drug use appears to be widespread and associated with many factors. It may be evidence based, since most is associated with conditions supported by the medical literature.