ABSTRACT

Purpose:

To evaluate whether valproic acid (VPA) treatment in children with epilepsy affects the plasma fatty acylcarnitine esters.

Materials and Methods:

Fifty children (mean age, 10±3.9) with epilepsy receiving VPA treatment for at least one year were evaluated along with 110 children of similar age as a control group. Levels of free carnitine and acylcarnitine profiles were studied with tandem mass spectrometry (Tan-dem-MS).

Results:

Free carnitine levels were within the normal limits. Valproic acid was found to affect the levels of the following individual acylcarnitines (medians): C4–acylcarnitine (0.56 μmol/L; controls 0.39 μmol/L), 3-hyd-roxy-isovalerylcarnitine (C5-OH) (0.23 μmol/L; controls 0.14 μmol/L), C14-acylcarnitine (0.11 μmol/L; controls 0.16 μmol/L), C16-acylcarnitine (0.76 μmol/L; controls 2.5 μmol/L), C16-OH-acylcarnitine (0.04 μmol/L; controls 0.07μmol/L), and C18:1-acylcarnitine (0.8 μmol/L; controls 0.97 μmol/L). A statistical comparison of these acylcarnitines between subjects and controls showed a statistically significant effect (p<0.05).

Conclusion:

The detection of normal free carnitine levels, the detection of 5-OH isovaleryl carnitine higher than other carnitines, and the normally found levels of some acylcarnitine fractions led us to conclude that VPA does not have a significant effect on the carnitine and acylcarnitine metabolism as a drug side effect when the carnitine metabolism is considered. Therefore, we think that a study of the acylcarnitine profile in addition to the detection of the levels of free carnitine is essential in understanding the exact effect of VPA on the carnitine metabolism.