RESUMO
BACKGROUND: In kidney transplanted children, it is difficult to obtain blood levels of mycophenolic acid between 2 and 4 microg/mL, when mycophenolate mofetil doses up to 30 mg/kg/d are given two or three times a day. We proposed that using mycophenolic acid, instead of the salt mycophenolate mofetil, may help us to reach target levels. AIM: We sought to describe the pharmacokinetics of mycophenolic acid in eight kidney transplanted children over a period of 1.2 +/- 0.8 years. PATIENTS AND METHODS: Eight patients (5 boys and 3 girls) aged 7.0 +/- 1.8 years received cadaveric kidney transplantations. Induction with basiliximab was followed by cyclosporine (n = 4) or tacrolimus (n = 4), tapered steroids (withdrawal at 12 months in six cases and maintained at 0.15 mg/kg/d in two cases), and mycophenolate mofetil (25 to 30 mg/kg/d two or three times a day). For 1.0 +/- 0.3 years mycophenolic acid levels were between 0.8 +/- 0.3 microg/mL. When mycophenolic acid sodium tablets were available, all patients were switched to this drug. RESULTS: After the conversion, blood levels obtained at 8 +/- 3 days were 1.5 to 5.0 microg/mL (median, 3.2), which were far closer to the target 2 to 4 microg/mL. No gastrointestinal disorders were observed with the follow-up of 72 +/- 18 days. CONCLUSION: Mycophenolic acid sodium reaches therapeutic levels whereas mycophenolate mofetil does not. If mycophenolic acid were available in syrup form, it could be used in patients under 5 years of age. It is necessary to follow these patients to rule out enzymatic induction.
