The Evaluation of Calcium Metabolism Markers and Their Correlation with Serum Levels of Anti Epilepsy Drugs in Children with Drug Resistant Epilepsy

Abstract

Determining the blood level of anti-epileptic drugs is essential in improving the treatment process of any patient with epilepsy, because long-term use of anti-epileptic drugs may have side effects. The aim of this study is to evaluation of calcium metabolism markers and their correlation with serum levels of anti epilepsy drugs in children with drug resistant epilepsy. Materials and Methods: This research is a descriptive-analytical cross-sectional study and among the children under 15 years of age referred to Tabriz Children's Education and Treatment Center in 2021, 66 children with drug resistant epilepsy with a history of at least six months of taking anti-epileptic drugs phenobarbital, phenytoin, and carbamazepine as single or multiple drugs after obtaining informed consent from their parents, were included in the study. The sampling method was available. The demographic characteristics of the people were recorded in the questionnaire forms. Venous blood sampling was done from all patients and after the collection of samples, serum levels of anti-epileptic drugs by high performance liquid chromatography (HPLC) were evaluated and recorded. Indicators of calcium, phosphorus, alkaline phosphatase, and magnesium with a biochemistry autovanizer; and vitamin D and PTH by ELISA method were evaluated and recorded. Finally, calcium metabolism indices were evaluated by statistical methods in terms of correlation with serum levels of antiepileptic drugs. Results: In this study, among the indicators of calcium metabolism, phosphorus had statistically significant relationships with phenobarbital (R=0.513; P-value=0.004) and carbamazepine (R=0.719; P-value=0.045) drugs in the studied children with drug resistant epilepsy. Vitamin D levels had a statistically significant relationship with phenytoin levels (R=-0.676; P-value=0.022). Also, calcium levels in the two-drugs group were significantly lower than the one-drug group in the studied children with drug resistant epilepsy (P-value=0.003).