Valproic acid malabsorption in 30 year-old female patient - Case study.

AIM: Valproic acid (VPA) is used in epilepsy treatment and as a stabilizer in bipolar affective disorder for over 40 years. Although, the pharmacokinetic properties of valproic acid are well known, it is often forgotten that the formulation of the drug significantly influences its gastrointestinal absorption.

CASE: We are describing the case of 30 year-old female patient, diagnosed at the age of 13 with juvenile myoclonic epilepsy. Complete ineffectiveness of the treatment was caused by malabsorption of sodium valproate and valproic acid in the patient. The change of the drug formulation resulted in a several times higher bioavailability of the drug and a partial improvement of the patient's clinical condition.

COMMENTARY: Low concentration of valproic acid after administration the slow-released tablets are usually observed. However, a low bioavailability beside the bad compliance should be considered when the minimal level is extremely low during therapy. It is known that form of the drug, beside presence of food and its components, as well as gastrointestinal tract condition or interactions with other drugs can influence the drug level. Modification of the formulation of the drug may lead to improvement of absorption and increase its effectiveness.