Pilot comparison of extended-release and standard preparations of divalproex sodium in patients with bipolar and schizoaffective disorders.

Abstract

The authors compared the new extended-release and standard preparations of divalproex sodium. Twelve patients with DSM-IV bipolar disorder or schizoaffective disorder who were clinically stable while taking the standard form of divalproex participated in the study. These patients were given a single daily dose of the extended-release preparation of divalproex in an open 6-week trial. Clinical symptoms and adverse effects were rated weekly. Doses were adjusted to maintain steady serum valproate concentrations. The medication change was associated with negligible changes in clinical status and tolerability. To maintain serum drug levels, however, 21% higher doses of the extended-release preparation were required. Use of extended-release divalproex once a day was as well tolerated as the standard preparation, with no change in efficacy within 6 weeks, but the daily dose needed to maintain stable serum valproic acid concentration was 21% higher.