Once daily dosage versus divided daily doses of carbamazepine therapy in epileptic patients: a pilot study.

The effect of once daily dosage of carbamazepine on fit frequency, electroencephalogram (EEG), behaviour and 24-hour drug levels were compared with those following 2 to 3 divided daily doses treatment. The 14 male epileptics, aged 16 to 18 years, who were studied had already been receiving carbamazepine for an average period of 2.5 years in combination with other anti-epileptic drugs. In this investigation, these patients received their usual daily dose (mean dose 13.9 mg/dg) of carbamazepine in 3-time, twice and once daily regimens. Each treatment period lasted for 4 weeks. Plasma concentrations of carbamazepine and its epoxide metabolite remained within the therapeutic range during the three treatment periods, but the area under the curves were greater during once daily medication. There was also slight decrease in the plasma sodium valproate concentration during the once daily regimen, but the concentrations of other concomitant medication remained unchanged. No significant changes in fit frequency and behaviour were observed athe area under the curves were greater during once daily medication. There was also slight decrease in the plasma sodium valproate concentration during the once daily regimen, but the concentrations of other concomitant medication remained unchanged. No significant changes in fit frequency and behaviour were observed athe area under the curves were greater during once daily medication. There was also slight decrease in the plasma sodium valproate concentration during the once daily regimen, but the concentrations of other concomitant medication remained unchanged. No significant changes in fit frequency and behaviour were observed and none of these patients suffered from any side-effects or toxic effects during once daily medication. EEG revealed a slight increase in abnormality during twice daily medication, but no further deterioration was seen during one daily treatment. In view of this observation, carbamazepine is probably effective as a single daily dose, but further long-term controlled clinical trial in necessary.