We appreciate Dr Cohen's comments on our article describing the clinical and humanistic outcomes associated with a therapeutic interchange of omeprazole with lansoprazole.1 In our article, we discuss the importance of considering patient-specific outcomes when therapeutic interchange is used as a process to maximize cost efficiency. It was this concern that prompted the initiation of our study. When decisions of therapeutic interchange are made, they must be accompanied by a systematic evaluation to ensure that patients who experience significant outcome deficits are treated appropriately. We describe such an attempt in our article. The reality of today's cost-containing health care environment, particularly in the area of pharmaceuticals, makes it fiscally irresponsible to suggest that therapeutic interchange be ignored as an approach to cost efficiency. In an era of fundamentally finite budgets, when marginal benefits do not outweigh enormous cost differences, we must move toward cost-efficient policies such as therapeutic interchange.