Low Serum Biotinidase Activity in Children with Valproic Acid Monotherapy

The study investigated the effect of valproic acid (VPA), an antiepileptic drug, on serum biotinidase activity in 75 children with seizures, who were divided into three groups based on their VPA dosage. Compared to 50 healthy controls, groups B and C, which received higher doses of VPA, showed significantly lower biotinidase activity (p < 0.001) and elevated liver function data. There was a strong inverse correlation between liver enzymes and VPA blood levels with biotinidase activity. However, no inhibitory effect on biotinidase activity was observed when the enzyme was incubated with high concentrations of VPA in vitro. Skin lesions such as seborrheic rash and alopecia improved after biotin supplementation (10 mg/day). The study suggests that VPA may impair liver mitochondrial function, leading to low biotinidase activity and potentially biotin deficiency, and that biotin supplementation could alleviate some VPA side effects.