DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Lower effectiveness of divalproex versus valproic acid in a prospective, quasi-experimental clinical trial involving 9,260 psychiatric admissions.

Author(s): Wassef AA, Winkler DE, Roache AL, Abobo VB, Lopez LM, Averill JP, Mian AI, Overall JE

Affiliation(s): Harris County Psychiatric Center, University of Texas Health Sciences Center, Houston, TX 77021, USA. awassef@mind.hcpc.uth.tmc.edu

Publication date & source: 2005-02, Am J Psychiatry., 162(2):330-9.

Publication type: Clinical Trial; Randomized Controlled Trial

OBJECTIVE: The authors examined clinical differences between divalproex sodium and generic immediate-release valproic acid. METHOD: This 6-year prospective, quasi-experimental clinical trial compared the effectiveness and tolerability of divalproex and valproic acid. The dependent variables were length of hospital stay, rehospitalization rate, and adverse drug reactions in 9,260 psychiatric admissions. RESULTS: Inpatients who initially received divalproex sodium had a 32.7% longer hospital stay and 3.8% higher readmission rate than did patients who initially received valproic acid. Initial treatment with divalproex prolonged length of stay by 30.3% in patients treated with divalproex and valproic acid during different admissions. After other variables were controlled by multiway analysis of variance, the hospital stay of patients who continued the initial medication was 15.2% longer (2.0 days) for divalproex than valproic acid. Switching medications was more common for valproic acid, partly because of study design. Medication intolerance occurred in approximately 6.4% more patients taking valproic acid than divalproex. However, switching from valproic acid to divalproex did not significantly prolong length of stay, over that for continuous divalproex, or increase the rehospitalization rate. CONCLUSIONS: Lower peak valproate concentrations with divalproex sodium may have enhanced tolerability but may also explain the lower effectiveness. Extended-release divalproex could lower effectiveness further and require higher doses. Thus, inpatients are better served by beginning with generic valproic acid and by changing to delayed-release divalproex only if intolerance occurs. This would save up to one-third of inpatient costs and two-thirds of a billion dollars yearly in medication costs.

Page last updated: 2006-01-07

-- advertisement -- The American Red Cross
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017