Valproic Acid Use Trends, Patterns, and Predictors in Females of Reproductive Age in the United States

Objective: To provide an up-to-date evaluation of valproic acid (VPA) use trends, patterns, and predictors in females of reproductive age in ambulatory care settings in the US.

Methods: A retrospective, cross-sectional study was conducted using 2017 through 2022 Medical Expenditure Panel Survey data to examine trends in VPA use. Prescription rates were calculated per 1,000 prescription events with 95% confidence intervals. VPA prescriptions were stratified by clinical indication and recipient group (females aged 12-49 years, females aged ≥50 years, and males aged 12-49 years). Multivariable logistic regression was used to identify predictors of VPA use among females aged 12-49 years and all females with comorbid bipolar disorder, headache, or seizure conditions.

Results: The cumulative total of VPA prescription events across the 2017-2022 study period was 29,754,849 (95% CI, 23,843,243-35,666,455). Of these, 5,442,682 (95% CI, 2,879,340-8,006,024) were issued to females aged 12-49 years (18.3% of all VPA prescriptions). From 2017 to 2022, VPA prescribing decreased by nearly 50% (P =.037). Most VPA prescriptions filled by females aged 12-49 years were for migraine or other headache syndromes (27.2%), followed by bipolar disorder (24.6%) and convulsions or epilepsy (20.7%). Of the estimated 153,120 females aged 12-49 years who filled a prescription for VPA between 2017-2022, 85.9% were not using contraception.

Conclusion: Approximately 1 in 5 VPA prescriptions between 2017 to 2022 were prescribed to females of reproductive age. VPA was most commonly used for the treatment of migraine or other headache syndrome, followed by bipolar disorder and convulsive disorder. Only 14.1% of females of reproductive age using VPA were also using contraception. Interventional studies aimed at reducing VPA use in females of reproductive age are needed.