A 15-year-old girl requiring sodium valproate for control of epilepsy after trying other anticonvulsants without success starts on 600 mg twice daily with dose increases every 3 days by 150–300 mg. Which adverse reaction is most likely to be observed when taking or using the medication?

• A. Alopecia
• B. Hypotension
• C. Hyperactivity
• D. Teratogenicity

Answer: (D)

Valproate carries a high risk of birth defects when used by females of reproductive potential, and this risk increases with higher doses. In a 15-year-old girl who could become pregnant, teratogenicity is the most clinically important adverse effect to anticipate and discuss. Exposure during early pregnancy can disrupt neural tube development, leading to defects such as spina bifida and other congenital anomalies. The fact she is on a relatively high daily dose (600 mg twice daily) heightens concern because higher exposure elevates this risk.

Alopecia, while possible with valproate, is less significant clinically and not as specific or critical in this scenario. Hypotension and hyperactivity are not characteristic concerns with valproate use.