Effects of Antiepileptic Drug Levels on Clinical Outcomes in Pediatric Patients Using Pharmacokinetics Approach

Abstract

The high prevalence of antiepileptic drug use in pediatrics increases the risk of side and toxic effects; therefore, it is necessary to monitor drug levels. Therapeutic drug monitoring is conducted through pharmacokinetics by calculating blood drug levels based on respondents' dose and frequency of therapy. This study aimed to determine the pharmacokinetics of antiepileptic drug levels and the correlation with clinical outcomes using descriptive observational design. Furthermore, the Indonesian Epilepsy Community collected respondents' data from June to July 2020 through online and telephone interviews. Out of the 11 respondents that recieved phenytoin, only 1 (9.09%) was in the therapeutic range (10–20 mg/L), while 10 (90.91%) were outside the therapeutic range (<10mg/L). From the 14 respondents that received phenobarbital, 8 (57.14%) were in the therapeutic range (15–40 mg/L), and 6 (42.86%) were outside the therapeutic range (<15 mg/L and >40 mg/L). From the 47 respondents that received valproic acid, 23 were administered through monotherapy, 7 (30.44%) were in the therapeutic range (50–100 mg/L), and 16 (69.56%) were outside the therapeutic range (<50 mg/L and >100mg/L). Out of the 24 respondents that received valproic acid as monotherapy, 18 (75%) were in the therapeutic range (50–100 mg/L), and 6 (25%) were outside the therapeutic range (<50 mg/L and >100mg/L). The results showed that there was no significant relationship (p>0.05) between drug levels and clinical outcome in respondents treated with either monotherapy or polytherapy of valproic acid. In conclusion, a total of 38 respondents (52.05%) had drugs levels outside the therapeutic range, while 35 (47.95%) had drug levels in the therapeutic range. Furthermore, respondents with drug levels outside the therapeutic range require direct monitoring of antiepileptic drug levels to avoid toxic effects and improve clinical outcomes.