PHARMACOKINETICS OF SULTHIAME IN EPILEPTIC PATIENTS

Sulthiame is an antiepileptic drug that was introduced approximately 3 0 years ago for the treatment of epilepsy. Currently it is rarely used , but recent studies show its efficacy, especially in the treatment of focal epilepsies in children. Because there are hardly any pharmacoki netic studies of sulthiame in humans, we studied the dose-level relati onship, the elimination half-life, and the daily fluctuations in the c oncentration of sulthiame among children and adults with epilepsy. The evaluation of the sulthiame serum concentrations of 86 patients gave, considering age and comedication, a relatively high correlation (r = 0.82) between the sulthiame dose/body weight and the sulthiame serum c oncentration. Children on a comparable sulthiame dose per body weight have lower sulthiame concentrations than adults. In our study sulthiam e was, with few exceptions, administered in combination with other ant iepileptic drugs. The sulthiame serum concentrations were lower in com edication with carbamazepine than with valproic acid. The evaluation o f the individual sulthiame dose-level relationship of 8 patients showe d in most cases a close and linear relationship. After withdrawal of s ulthiame in 11 patients, short elimination half-lives (8.65 +/- 3.10 h ) were estimated. This was in accordance with the large daily fluctuat ions in the sulthiame concentrations (swing: 103.9 +/- 59.3%) of the n ine patients examined. The shorter half-fives and higher daily fluctua tions in children indicate a higher clearance of sulthiame among child ren.