Valproate, plasma or serum

Valproic acid is used in the treatment of patients with complex partial seizures which occur either alone or in association with other types of seizures. Valproic acid may be used solely or in combination with other anticonvulsant drugs. The capability of treating many different types of seizures has resulted in the wide-spread use of valproic acid, particularly in children. Most patients receiving valproic acid do not develop a tolerance to its anticonvulsant effects. Valproic acid is generally well tolerated, with the most common side effects being: headache, gastrointestinal (nausea, vomiting, diarrhea), nervous system (tremors) and thrombocytopenia.