Reply to Letter to the Editor "Gastrointestinal Adverse Effects With Divalproex Sodium and Valproic Acid"

Letter to the Editor

Sir: In their letter, Wagner and colleagues report that, in contrastto our article, they were able in an open-label fashion tosuccessfully switch 98 inpatients from divalproex sodium to valproic acid without an increased incidence in gastrointestinalside effects. On the basis of their observations and those of 2other studies, they conclude that these preparations are interchangeableand that switching from divalproex to the less costlyform of the drug, immediate-release valproic acid, should beconsidered.

There are now an increasing number of reports on the replacementof divalproex sodium with valproic acid. Some reportssuggest that the switch can be done successfully and thatsubstantial cost savings may be achieved.