Therapeutic carbamazepine (CBZ) and valproic acid (VPA) monitoring in children using saliva as a biologic fluid

• Autor(a) principal: Maldonado,C.
• Data de Publicação: 2008
• Outros Autores: Fagiolino,Pietro, Vázquez,M., Rey,A., Olano,I., Eiraldi,R., Scavone,C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of epilepsy and clinical neurophysiology (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1676-26492008000200003
• topic: Saliva concentration; carbamazepine; valproic acid; refractory epilepsy; efflux transporters

OBJECTIVE: The aim of the study was to analyze retrospectively carbamazepine (CBZ) and valproic acid (VPA) salivary data collected from epileptic children during a 3-year period. METHODS: Saliva samples stimulated by citric acid were assayed by FPIA method. One hundred and three patients (aged 1-14 years) were in CBZ or VPA monotherapy or in CBZ-VPA combined therapy. RESULTS: VPA salivary levels were linearly related with daily dose, but a non-linear relationship was found for CBZ, in patients under monotherapy. VPA did not alter saliva CBZ concentration. Conversely, CBZ reduced VPA salivary levels. Non-responsive children displayed higher VPA concentrations. CBZ levels in uncontrolled patients showed non-significant difference in relation with controlled subjects even though their daily doses were higher. CONCLUSION: Citric acid stimulated saliva is reliable enough to perform therapeutic drug monitoring. Saliva drug levels in non-responsive patients would be explained according to the generalized efflux transporter overexpression hypothesis.