Clinical outcomes associated with conversion from brand-name to generic tacrolimus in hospitalized kidney transplant recipients

Purpose. The safety of converting kidney transplant recipients on brand-name tacrolimus to generic tacrolimus during hospitalization was evaluated. Methods. A single-center observational study compared tacrolimus dosages and trough tacrolimus levels in kidney transplant recipients who had a kidney transplant more than 90 days before hospital admission. Patients in the "brand" group were maintained on brand-name tacrolimus throughout the entire study period. Patients in the generic group were maintained on brand-name tacrolimus before hospital admission, converted to the generic formulation during hospitalization, and returned to the brand-name product at discharge. Tacrolimus dosages were converted on a milligram-per-milligram basis and adjusted, if needed. Outcomes evaluated included the percentage of patients requiring a dosage change, absolute change in average tacrolimus trough level, and frequency of biopsy-proven acute rejection within six months of discharge. Results. A total of 100 patients were evaluated for inclusion in the brand group, with 42 meeting study criteria; 98 patients were evaluated in the generic group, with 36 qualifying for the study. There were no significant differences between the brand and generic groups with respect to dosage adjustments required or trough tacrolimus levels at any point in the transition of care. Mean trough concentrations were similar between groups during all periods of care. The only occurrence of new-onset acute rejection within six months after admission occurred in the brand group., Conclusion. Substitution of a generic formulation of tacrolimus for the innovator product during hospitalization of kidney transplant recipients was safely implemented. Tacrolimus dosage adjustments were common throughout the transitions of care, regardless of the formulation used.