An investigation on the effects of carbamazepine and sodium valproate on neuromuscular transmission

The aim of this study was to investigate the effects of sodium valproate (SV) and carbamazepine (CBZ) on neuromuscular transmission using single-fibre electromyography (SFEMG) in patients with epilepsy. We performed SFEMG during the voluntary contraction of extensor digitorum communis muscle. 30 epileptic patients taking SV, 25 epileptic patients taking CBZ, and 25 age-matched healthy volunteers were included in the study. Mean jitter values (MCD) of subjects taking SV and CBZ were compared with normal controls. MCD values of subjects taking SV and CBZ were statistically significantly higher than those of control group. Review of the correlation between disease duration and MCD values of patients showed that MCD values were increased with the prolonged use of drugs, and thus, indicated a positive relationship between these two parameters. These results suggest that both SV and CBZ reduce neuromuscular transmission in patients without a neuromuscular junction disease.