Issues in formulary management: therapeutic interchange. The value, cost, and quality of therapeutic interchange.

Therapeutic interchange is a process of substituting a prescribed medication with one that offers therapeutic and cost benefits. The practice not only provides short-term savings but also is associated with decreases in lengths of stay in hospitals and total hospital drug expenses. There may be medicolegal implications when FDA-approved indications differ for interchanged drugs. The potential for liability is decreased when a standard of care is met, but since standards can change, guidelines should be reviewed regularly. High-tech, high-cost drugs are sometimes appropriate for therapeutic interchange. Pharmacy and therapeutics committees should assure best value by considering indirect expenses, quality, and therapeutic outcome, as well as product cost. Therapeutic interchange programs enable pharmacy managers to neutralize or at least slow the rate of drug cost increases, ensuring appropriate utilization of resources and more favorable patient outcomes.