RESUMEN
Epilepsy is resistant to drug treatment in about one third of cases, but the mechanisms underlying this drug resistance are not understood. The aim of this study is to assess carbamazepine [CBZ] effect on homocysteine and folic acid occurrence in patients with epilepsy. A total of 45 epileptic outpatients treated by CBZ and 28 sex and age matched healthy controls. The mean of homocysteine and folic acid in epileptic patients were significantly higher 16.46 +/- 1.79 micro mol/L; 8.46 +/- 0.35 ng/ml compared with healthy controls 8.54 +/- 0.64; 10.61 +/- 0.63 [p = 0.0001; p = 0.006, respectively]. Epileptic patients were divided into two groups, therapy-response, and therapy-resistant. Homocysteine serum concentration was significantly higher in the first group of patients [therapy-resistant] compared with healthy controlled group 19.77 +/- 2.96 versus 8.54 +/- 0.64 [p = 0.0001], respectively. However, folic acid concentration was significantly lower in the first group of patients [therapy-resistant] compared with healthy controlled group 7.58 +/- 0.3 versus 10.61 +/- 0.63 [p = 0.001] respectively. In therapy-response group, homocysteine serum concentration was significantly different compared with healthy controlled group [12.3 +/- 1.11 versus 8.54 +/- 0.64], but it remained within the normal value. There was no significant difference in levels of folic acid between the therapy-response group and healthy controlled group 9.55 +/- 0.61 versus 10.61 +/- 0.63 [p = 0.21]. This study demonstrates that epileptic patients taking antiepileptic drug [CBZ] have increased serum levels of homocysteine. Serum homocysteine levels in patients treated with CBZ were higher - up to 50%. The elevated levels of homocysteine may occur due to deficiency of folic acid that is necessary for homocysteine metabolism