A QSP Model of Valproic Acid Toxicity in Pediatric and Adult Populations: Implications for Formulation Selection and L-Carnitine Supplementation.

The QSP model successfully predicted overall incidences of VPA-induced hyperammonemia, hyperlipidemia, and hepatotoxicity that aligned with previously reported clinical data.

• Predicted overall incidence of hyperammonemia was 29%.
• Predicted overall incidence of hyperlipidemia was 54%.
• Predicted overall incidence of hepatotoxicity was 2%.
• These predictions aligned with previously reported clinical data.

The model revealed distinct age-dependent toxicity patterns, with significantly lower incidences of adverse effects in toddlers compared to children and adult women.

• Four demographic groups were modeled: toddlers (0–2 years), children (2–14 years), women (14–40 years), and men (14–40 years).
• Age-appropriate dosing regimens were simulated: 35 mg/kg/day for toddlers, 25 mg/kg/day for children, and 15 mg/kg/day for adults.
• Toddlers showed significantly lower toxicity incidences compared to children and adult women.
• Children and adult women showed similar toxicity profiles to each other.

Extended-release formulations showed consistent directional trends toward lower adverse effect incidences compared to delayed-release formulations across all toxicity endpoints.

• Formulation comparison was conducted across all demographic groups modeled.
• The trend toward lower adverse effect incidences with extended-release formulations was consistent across hyperammonemia, hyperlipidemia, and hepatotoxicity endpoints.
• The finding provides evidence-based support for formulation selection in VPA therapy.

L-carnitine supplementation administered at twice the VPA dose (in mg) was quantitatively assessed to effectively prevent hyperammonemia and maintain physiological fatty acid levels.

• The model quantitatively assessed L-carnitine supplementation (CS) benefits across the virtual populations.
• The recommended dosing ratio identified was L-carnitine at twice the VPA dose in mg.
• This supplementation level was predicted to prevent hyperammonemia.
• The supplementation also maintained physiological fatty acid levels.

The study extended a previously developed QSP model by incorporating age, sex, and formulation-related covariates to characterize VPA-induced toxicity across diverse populations.

• Virtual populations representing four demographic groups were developed: toddlers (0–2 years), children (2–14 years), women (14–40 years), and men (14–40 years).
• The model incorporated covariates for age, sex, and drug formulation type.
• VPA is described as a widely prescribed short-chain fatty acid for managing epilepsy, psychiatric conditions, and migraines.
• The model addresses three major toxicity outcomes: hyperammonemia, hyperlipidemia, and hepatotoxicity.