The use of therapeutic interchange for biologic therapies.

Therapeutic interchange is the practice of switching or dispensing drugs that are chemically distinct but therapeutically similar in terms of their efficacy, safety, and tolerability profiles. The stated goal of therapeutic interchange is to achieve an improved or neutral outcome with the new agent while reducing overall treatment costs. Until recently, most interchange programs have been limited to switches within drug classes, such as angiotensin-converting enzyme (ACE) inhibitors, proton pump inhibitors (PPIs), HMG-CoA reductase inhibitors (statins), and selective serotonin reuptake inhibitors (SSRIs), and generally to drugs that use the same routes of administration. Therapeutic interchange now is being applied to some biologic agents, such as those used to treat psoriasis and rheumatoid arthritis (RA). In some cases, these agents differ in structure and mode of administration. Patients who require a biologic agent are often difficult to manage, and the comorbidities that are prevalent in these patients further complicate management and agent selection. Population-based outcomes among various agents may not appear notably different, but because there is no a priori means to determine the effects of a given biologic agent on any individual patient, therapeutic interchange is inadvisable once a patient receiving RA or psoriasis therapy has been stabilized. However, if a biologic agent has been designated as preferred on a formulary, it is reasonable to initiate treatment with that agent in a patient who is naive to biologic therapy if that agent is not contraindicated. Respectful, two-way communication between health care professionals and managed care organizations (MCOs) will help ensure that a patient receives the appropriate therapy at the right time.