Salivary antiepileptic drug levels in Thai children.

A total of 123 patients were enrolled in this study. 88 patients were enrolled in the first stage of the study, which was to evaluate the commercial salivary collecting devices: Orasure and Omnisol. 35 patients were enrolled in the second stage of the study and were asked to spit whole saliva samples for further analysis of AED levels. Serum AED levels and corresponding saliva AED levels were paired and analyzed for the correlation coefficients with the linear regression model. None of the commercial salivary collecting devices can provide the linear regression correlation between the serum AED level and saliva AED level in all three AEDs studied. The correlation coefficients of serum and whole saliva AED levels of phenobarbital, phenytoin, and carbamazepine were highly correlated (r-squared were 0.981, 0.976, and 0.888, respectively). Saliva samples can be used clinically to monitor the AEDs level in phenobarbital, phenytoin and carbamazepine. This would be another alternative method of therapeutic drug monitoring that can be done painlessly and is easier in children than the blood sampling method.