Carnitine levels and cardiac functions in children with solid malignancies receiving doxorubicin therapy

Previous studies demonstrated l-carnitine decreasing doxorubicin-induced cardiotoxicity. Our objectives were to study carnitine levels and cardiac functions in children treated with doxorubicin and the effect of short-term l-carnitine supplements.

Serial carnitine levels and cardiac functions were obtained in children with newly diagnosed solid malignancies before doxorubicin, after cumulative doses of ≥150 mg/m(2) and ≥300 mg/m(2), respectively. Oral l-carnitine 100 mg/kg/day for 3 days were given to the children treated with doxorubicin at cumulative doses of ≥150 mg/m(2) and ≥300 mg/m(2). Carnitine levels and cardiac functions were also obtained in those children before and after short-term oral l-carnitine at each cumulative dose of doxorubicin.

Five children (3 females), median age of 9.1 years (range 1.5-13 years) with newly diagnosed solid malignancies were enrolled in the study. Free carnitine (FC) tended to decrease while acyl-carnitine (AC) increased making AC/FC ratio increased after cumulative dose of ≥150 and ≥300 mg/m(2) but the statistics was not significant. Left ventricular (LV) systolic function was not significantly changed. Interestingly, LV global function (LV myocardial performance index) was significantly increased after 150 mg/m(2) (median 0.39, 0.27-0.51) and 300 mg/(2) (median 0.46, 0.27-0.50) when compared to baseline (median 0.28, 0.14-0.48) (P=0.05). Carnitine levels and cardiac functions were not significantly changed after oral l-carnitine supplement at cumulative dose of ≥150 mg/m(2) (n=6) and ≥300 mg/m(2) (n=9).

Carnitine levels tended to decrease after doxorubicin treatment. LV global dysfunction was documented early after doxorubicin. However, short-term l-carnitine supplement did not improve cardiac function.