The effect of MMF dose and trough levels on adverse effects in pediatric heart transplant recipients

Limited pharmacokinetic and safety data exist for MMF in pediatric HTR. Previously targeted MPA‐TL are 1.5–3.0 μg/mL. The objective of this study was to assess the outcomes targeting MPA‐TL of 0.8–2.0 μg/mL in pediatric HTR. MPA‐TL were retrospectively collected 2–12 months post‐transplant. Acute rejection, infection, leukopenia, and GI complaints were then correlated with MPA‐TL. A total of 355 MPA‐TL from 22 HTR were included. Median age was 2.5 yr. Primary indication for transplant was dilated cardiomyopathy (64%). Mean MPA‐TL was 1.7 ± 0.9 μg/mL. African American patients received significantly higher doses (702 ± 235 mg/m²) compared with other races (p = 0.035). Leukopenia was less common in patients with SUB MPA vs. others (p = 0.01). MMF was discontinued for GI complaints in one patient and leukopenia in two patients. One SUB patient had acute rejection, and one SUP patient had infection. One‐yr survival was 100%. Targeting a lower range for MPA‐TL was not associated with significant rejection or infection. Despite lower MPA‐TL, MMF was discontinued in 3/22 patients for adverse effects.