Valproic acid therapy and hypothyroidism

Article Outline

• Copyright

In a cross-sectional case-control study including 143 children with chronic epilepsy treated with valproic acid, Mikati et al report in this issue of The Journal that 25% had mildly elevated (>5 mIU/L) serum thyroid stimulating hormone level. Subgroup analysis identified young age, therapy of 6-to-24 month duration, and concurrent receipt of other anti-epileptic drugs as risk factors for subclinical hypothyroidism. If confirmed in subsequent study, the findings have important implications. Subclinical hypothyroidism may not be benign when considering brain growth and development. Valproic acid has been used widely, not only for epilepsy, but for psychiatric indications and treatment of migraine syndromes for decades. Data regarding potential multisystem effects are limited.