IS SALIVA SUITABLE FOR THERAPEUTIC MONITORING OF ANTICONVULSANTS IN CHILDREN - AN EVALUATION IN THE ROUTINE CLINICAL SETTING

Studies performed in the research setting suggested that saliva instea d of blood may be used for therapeutic drug monitoring (TDM) of antico nvulsants in children. This is an attractive alternative because its c ollection is painless, and simpler and cheaper than blood drawing. Cit ric acid stimulation of saliva secretion facilitates sampling in the y oungest patients, The aim of the study was to evaluate the suitability of saliva in routine TDM of anticonvulsants in infants and children w ith epilepsy. Blood and saliva samples were obtained simultaneously du ring routine TDM in 170 patients on chronic anticonvulsant drug therap y attending a neurology clinic. Saliva, plasma total, and plasma free concentrations of anticonvulsants were measured by high-performance li quid chromatography and enzyme multiplied immunoassay technique. Stron g and highly significant correlations between saliva and plasma concen trations were found over a wide range of concentrations for carbamazep ine, phenytoin, clobazam, and desmethylclobazam, and for phenobarbital in children greater than or equal to 8 years of age (r = 0.90 to 0.97 ; p < 0.001). Correlations between saliva and plasma concentrations we re poor for phenobarbital in children <8 years of age and for valproat e. Correlations between saliva and plasma-free anticonvulsant concentr ations were equal or only slightly better than between saliva and plas ma total concentrations, Citric acid-stimulated saliva constitutes a c onvenient alternative for TDM of carbamazepine and phenytoin therapy i n pediatric patients and of phenobarbital in children greater than or equal to 8 years of age.