臓器移植における免疫抑制薬の後発医薬品（ジェネリック医薬品）の現状

抄録

The use of the generic drugs reduces the drug costs for the treatment, resulting in sparing the economic burden on patients and medical insurance system. Generic drugs are basically same with the innovator drug in bioequivalent study employing healthy subjects, though the rigorous criteria on the equivalence is required for high-risk drugs such as immunosuppressants. Meta-analysis of bioequivalent study on cyclosporine, tacrolimus, and mycophenolate mofetil in solid organ transplant recipients failed to meet equivalent criteria, though no significant difference in the incidence of acute rejection is observed between generic and innovator ones. There is still controversial on the use of generic immunosuppressants for organ transplantation due to the limited evidence and information. Therefore, when switching innovator to generic drugs, it is desirable to measure the blood concentration in therapeutic drug monitoring (TDM) and confirm changes in blood concentration before and after the switching. In the case of cyclosporine, authorized generic (AG) that is same product with innovator and inexpensive have been launched in Japan. AG is desirable generic products in the field of high-risk drugs including immunosuppressants. Since immunosuppressants such as calcineurin inhibitors and mycophenolic acid have a large intra-individual pharmacokinetic variability, it is required to assess the difference in contribution on the variability between generic and innovator drugs.