Effect of antiepileptic drugs on liver enzymes

This study was conducted to assess the effect of carbamazepine, sodium valproate and phenytoin on serum liver enzymes in 49 epileptic patients admitted to the neurology outpatient clinic at Beni-Suef University between February 2010 and June 2011. The patients were separated into group I (16 patients) treated with 200–1200 mg/day carbamazepine; group II (16 patients) treated with 200–800 mg/day sodium valproate; and group III (17 patients) treated with 200–400 mg/day phenytoin. Serum liver enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and serum level of antiepileptic drug were determined. No patient developed clinical symptoms of liver disease. Hepatic enzymes abnormal values were seen in 51.9% (n = 27) in the three study groups. In group I, the alterations at ALP enzyme were 50% (n = 8). In group II, the alterations at ALT were 6.25% (n = 1) and at ALP were 62.5% (n = 10). In group III, the alterations at AST were 5.88% (n = 1), at ALT were 17.65% (n = 3) and at ALP were 23.53% (n = 4). There was a statistically significant positive correlation between the dose/kg of carbamazepine and the serum level of the drug, a statistically significant positive correlation between the dose/kg of sodium valproate and AST and a statistically significant negative correlation between the duration of administration of sodium valproate and AST. There was also a statistically significant negative correlation between the duration of administration of carbamazepine and AST and ALP. In conclusion, sodium valproate was more hepatotoxic than carbamazepine which was more hepatotoxic than phenytoin. The routine screening of hepatic enzymes level during the chronic use of antiepileptic drugs is recommended.