The Comparison of Salivary and Serum Levels of of Phenobarbital and Phenytoin in Children with Status Epilepticus and Refractory Status Epilepticus

Abstract

The aim of this study is to comparison of salivary and serum levels of of Phenobarbital and Phenytoin in children with status epilepticus and refractory epilepticus. Materials and Methods: This study was cross-sectional study and was performed on 50 children (in two groups of status epilepticus and refractory epilepticus with matched average age and sex) among children under 15 years of age with status epilepsy who were admitted to Children's Educational and Medical Center of Tabriz from February 2019 to February 2020 after obtaining the informed consent of their parents, they entered the study (inclusion criteria). The sampling method in this study was available. Among all patients who were taking antiepileptic drugs regularly before the onset of status epilepticus and shortly before to prescribe the next daily dose of the drug, were performed venous blood sampling and collection of saliva samples. Then, serum and salivary levels of phenobarbital and phenytoin drugs were evaluated by high performance liquid chromatography (HPLC). Results: In this study, the subjects included 22 patients (44%) (14 boys and 8 girls) with status epilepticus and 28 patients (56%) (16 boys and 12 girls) with refractory epilepticus. In this study, the mean (standard deviation) of age in the two groups of status epilepticus and refractory epilepticus was 4.70 (3.04) and 4.94 (2.93) years, respectively (p = 0.776). There was no statistically significant difference between the two groups in terms of mean age and sex ratio (p <0.05). There was no significant difference between the status epilepticus and refractory epilepticus groups in terms of the serum (27.68 ± 12.44, and 25.38 ± 11.57, respectively, µg/mL; p=0.503) and saliva (9.79 ± 4.97, and 8.95 ± 4.72, respectively, µg/mL; p= 0.542) levels of phenobarbital. Also, there was no significant difference between the status epilepticus and refractory epilepticus groups in terms of the serum (11.37 ± 2.08, and 12.30 ± 2.41, respectively, µg/mL; p=0.330) and saliva (2.12 ± 0.65, and 2.10 ± 0.68, respectively, µg/mL; p= 0.951) levels of phenytoin. The ratio of serum to salivary phenobarbital levels in the status epilepticus and refractory epilepticus were 3.03 ± 0.75 and 3.10 ± 0.91, respectively, which were not significantly different (p=0.765). Also, in the case of phenytoin, there was no significant difference between the status epilepticus (5.79. ± 1.58) and resistant epilepsy (6.10 ± 1.04) (p=0.635). There was a significant positive correlation between serum and salivary levels of phenobarbital in both groups of status epilepticus (p <0.001, r = 0.966) and refractory epilepticus (p<0.001, r=0.949). Serum and salivary levels of phenytoin also had a significant positive correlation in both groups of status epilepticus (p=0.030, r=0.464) and refractory epilepticus (p = 0.001, r=0.959).