Generic maintenance immunosuppression in solid organ transplant recipients.

Survival after solid organ transplantation has increased in the era of tacrolimus and mycophenolate. This increased survival could be due in part to the broad clinical use of these potent and specific agents for maintenance immunosuppression. These drugs have enhanced specificity and potency for T and B lymphocytes compared with their predecessors, cyclosporine and azathioprine. Between 2008 and 2010, the United States Food and Drug Administration approved several generic formulations of both tacrolimus and mycophenolate mofetil. Deciding whether generic products can be safely substituted for the innovator product is a clinical dilemma similar to that which occurred when generic formulations of cyclosporine became available. We describe the concerns regarding generic immunosuppression use, summarize expert opinion and consensus statements in transplantation, analyze the potential impact of generic substitution, and provide estimates of populations affected based on generic drug market penetration. Formulary considerations such as cost, availability, and potential drug ordering and drug selection errors are described, and transplant coordinator and patient perspectives are reviewed. Finally, general recommendations about the use of generic maintenance immunosuppression in solid organ transplant recipients are provided. Although more research is needed to confirm clinical and therapeutic equivalence and pharmacoeconomic benefit, generic immunosuppressants can be safely substituted for innovator products as long as patients consistently receive the same product, patients and clinicians are aware of when substitutions occur, and enhanced therapeutic drug monitoring is provided during the transition.