A major international study published in eClinicalMedicine, by colleagues at UCL, Aston University, WHO and UKHSA has found that while global consumption of antiseizure medications (ASMs) rose steadily between 2012 and 2022, access to modern epilepsy treatments remains highly unequal across countries, and sodium valproate continues to be the most-used ASM worldwide.
Central to the findings is valproate. Its use has declined in many high-income countries (HICs) but has increased in numerous low- and middle-income countries (LMICs), despite long-standing safety warnings about exposure during pregnancy, which is associated with congenital malformations and neurodevelopmental disorders. Regulators advise avoiding valproate in people who could become pregnant unless no suitable alternative is available, alongside robust pregnancy-prevention measures.
The study, the largest of its kind, analysed pharmaceutical sales data from 73 countries and found that average ASM use grew from 3.10 to 3.95 daily doses per 1,000 people per day over the decade. However, HICs consumed far more and transitioned to newer, safer drugs earlier, while many LMICs continue to rely on older medications.
“This is not only about access, it’s about safe access,” said corresponding author Dr Kenneth Man. “Where alternatives like lamotrigine and levetiracetam aren’t consistently available, clinicians face difficult trade-offs and many health systems default to valproate. Closing that gap is a global priority.”
In 2022, North America recorded the highest ASM use (15.48 daily doses per 1,000 inhabitants), followed by Oceania (11.19) and Europe (8.73). Asia (1.98) and Africa (4.78) had significantly lower levels. The gap is partly driven by affordability: newer-generation ASMs cost more and are less consistently available in resource-limited settings.
The authors warn that inequities in access to newer ASMs risk widening treatment gaps and could affect maternal–child health where valproate remains widely used.
The study underscores the urgency of global action to ensure equitable access to neurological care.