Extended-Release Divalproex Sodium for Mood Stabilization

Efficacy, Safety, and Retention Rate of Extended-Release Divalproex Versus Conventional Delayed-Release Divalproex: A Meta-Analysis of Controlled Clinical Trials

Purpose: A novel once-daily divalproex-extended release (ER) dose formulation has been developed; this formulation prolongs the therapeutic serum levels of the drug, compared with the twice-daily conventional divalproex-delayed release (DR) formulation. This study aimed to systematically examine and compare the efficacy, safety, and retention rates of the ER divalproex (VPA-ER) and conventional DR divalproex (VPA-DR) formulations.

Methods: Randomized control trials (RCTs) reporting the efficacy, adverse events (AEs), and medication compliance of ER and DR divalproex were searched in online databases, including PubMed, Embase, and Cochrane Library databases, by searching MeSH words and term words. Observational studies with potential biases were excluded. The meta-analysis was performed using Stata 16.0 software.

Findings: Thirteen RCTs, involving 1,028 participants, were included in this meta-analysis. Efficacy, AEs, and drug retention rates were the main study outcomes. According to our study, VPA-ER presented clinically significant benefits compared with the placebo in the population with bipolar disorder (BD) (39.5% versus 27.2%, p < 0.001). A similar efficacy of VPA-ER and VPA-DR in controlling seizures was observed in epilepsy patients (87.4% versus 86.5%, p = 0.769). A significantly lower incidence of AEs was reported in the VPA-ER group than in the placebo group (26.8% versus 34.8%, p = 0.003). By contrast, there was no evidence of difference in safety between VPA-ER and VPA-DR (29.4% versus 30.5%, p = 0.750). In addition, the drug retention rate was significantly lower in the VPA-ER group than in the placebo group (76.0% versus 82.7%, p = 0.020), especially in migraine patients (p = 0.022) and in patients who were treated for fewer than 4 weeks (p = 0.018).

Implications: The efficacy of VPA-ER was significantly superior to that of the placebo treatment, which provided efficacy similar to that of conventional VPA-DR. VPA-ER is well tolerated with a low rate of AEs compared to the placebo. In addition, the acceptable medicine compliance of VPA-ER was conducive to the long-term maintenance treatment of chronic diseases. Although we analyzed open labels and crossover design RCTs, large-scale multicenter studies on the efficacy and medicine compliance of new ER formulations with less AEs are required to validate our conclusion.

Therapeutic drug monitoring with valproate–Why product selection is an important factor

There is a modest collection of literature describing the pharmacokinetic and clinical differences between the extended-release form of divalproex sodium (Depakote ER®) and the delayed-release form (Depakote®). Published articles are quick to espouse the extended-release formulation, especially in the setting of seizure control. Reasons commonly cited include a longer dosing interval, improved patient compliance, a more consistent pharmacokinetic profile, and fewer side effects. There are fewer articles discussing these differences in the context of treating mental illnesses, namely bipolar affective disorder. This article aims to compare these two formulations of divalproex with a special focus on their pharmacokinetic profiles, uses in psychiatric illness, and the role of therapeutic drug monitoring. The patient case that follows will describe a scenario in which a patient was prescribed each formulation during an acute hospitalization.

Extended-release divalproex in bipolar and other psychiatric disorders: A comprehensive review

Bipolar disorder can be a devastating disease state for individuals with the disease and also for family members. Proper recognition and treatment is vital to the successful management of this disease state. Through increased community and practitioner awareness, along with efforts to increase awareness for proper assessment, the rate of diagnosed bipolar disorder is increasing. Recent years have brought about the introduction of several new medications with approved indications for the treatment of bipolar disorder. In addition to new agents, traditional mood stabilizing medications have also been released in different formulations to better enhance tolerability without jeopardizing efficacy. One particular product is extended-release divalproex sodium. In the following article, we review the clinical presentation of bipolar disorder, its epidemiology, and the pharmacokinetics and mechanism of action for divalproex. In addition, we specifically review the role of extended-release divalproex in bipolar disorder through a critical analysis of the currently available published primary literature.

Rapid oral loading of extended release divalproex in patients with acute mania

BACKGROUND

Oral loading with the delayed release formulation of divalproex sodium is widely used for the treatment of patients with acute mania and produces rapid attainment of therapeutic serum levels. Recently, an extended release formulation of divalproex sodium (divalproex ER) was approved for treatment of migraine headaches. This formulation may be a useful treatment option for patients with acute mania.

METHOD

A retrospective review of medical records was conducted on 14 inpatients with acute mania whose treatment included initiation of divalproex ER at a dose of 30 mg kg(-1) day(-1) in a single dose. Doses, serum levels and side effects associated with this treatment were recorded from the medical records of these patients.

RESULTS

The average dose of divalproex ER was 2034 mg day(-1) (range, 1500-3000 mg day(-1)). Two of the 14 patients (14%) had documented side effects, none of which were severe. The average level obtained on day 3 after initiation of divalproex ER treatment was 93.2 mug ml(-1) (range, 47-136 mug ml(-1)), and in all but three patients valproate levels at this time point were within the therapeutic range of 50-125 mug ml(-1). In no case was divalproex ER discontinued due to a perceived lack of efficacy.

CONCLUSION

The results suggest that divalproex ER can be safely administered by oral loading in inpatients with acute mania and that using a standard loading protocol can result in therapeutic serum levels in most patients in 3 days or less.