Effects of valproic acid, carbamazepine, and phenobarbitone on the fatty acid composition of erythrocyte membranes in children

Purpose: To investigate a possible relation between antiepileptic drugs (AEDs) and the fatty acid composition of membranes. Methods: Fatty acid (FA) composition of erythrocytes was studied in children with epilepsy receiving AED monotherapy. Children taking valproate (VPA, n = 28), carbamazepine (CBZ, n = 17), or phenobarbitone (P13, n = 14) were compared with healthy controls (n = 25) FAs were measured by capillary-gas chromatography (GC-FID). Results: Significant changes (p < 0.05) in the FA composition of membranes were found. In children treated with VPA, C13:0 was decreased (8.2 +/- 2% vs. 10.7 +/- 4% in controls) and C14:0 increased (1.4 +/- 0.5% vs.1 +/- 0.5% in controls). C17:0 again was reduced (9.9 +/- 4% vs. 13.2 +/- 6% in controls), whereas the long-chained acids were enhanced: C18:2n-6 (6 +/- 2.4% vs. 3.9 +/- 2.5% in controls), and C20:4n-6 (1.9 +/- 1.7% vs. 1.4 +/- 0.5% in controls). The nonidentified FAs also increased with VPA therapy: 2.5 +/- 0.8% versus 1.7 +/- 0.9% in controls. Children treated with CBZ showed only minimal changes of FA composition: C 13:0 was decreased compared with controls (8 2% vs. 10.7 4%). No changes were seen in patients taking PB. The mean corpuscular volume (MCV) showed important differences between the study groups: MCV was 84.7 +/- 6.0 fl during VPA therapy (p < 0.001) and 85.7 +/- 4.1 fl with CBZ (p < 0.001). During PB, the MCV increased to 82.87 +/- 3.29 fl compared with controls (78.73 +/- 4.92 fl; p < 0.01). Conclusions: VPA therapy is associated with changes of the FA composition of membranes, which is not the case with PB therapy. The implications of this finding remain to be established.