Review of Sodium Valproate Clinical and Biochemical Properties

Valproic acid is a commonly used anti-epileptic drug (AED) for prescription to control convulsion attacks. The aim of this study was to provide a review of drug management among adult epileptic population. Topic words that searched were “Valproic acid, Pharmacokinetics, Epilepsy and Iran” that search in DOAJ, Google Scholar, PubMed and Web of Science. A total of approximately 1200 articles were found and at the end, 41 articles were reviewed. With an oral dose of 10 - 15 mg/kg/day in three divided doses, target blood level ranges from 50 - 100 mg/L. With a half-life of 9 - 16 hours, it seems that the valproic acid has a variable absorption phase. The pattern of metabolic pathways seems to be through the glucuronide conjugation and mitochondrial B-oxidation. The drug causes delay in carbamazepine elimination and may increase the amount of its metabolites. Valproic acid could decrease the clearance of amitriptyline and nortriptyline. Aspirin increase its’ trough level. The doses of olanzapine suggested to be reduced when co-medicated with valproic acid. To specify the amount and effects of administrated dose an attentive pharmacotherapy- guideline seems to be useful. Due to CYP450 dependent metabolic pathways (inhibition or induction), therapeutic drug monitoring (TDM) in simultaneous prescription of valproic acid with carbamazepine, lamotrigine, phenytoin, topiramate, amitriptyline, nortriptyline, aspirin, meropenem, olanzapine and clonazepam, manifested to be necessary in clinical practice.