ABSTRACT

Monitoring levetiracetam plasma concentration is not frequently used in clinical practice due to the linear pharmacokinetics of the drug and the absence of drug interactions. Nonetheless, some studies mention pharmacokinetic interactions of the drug and suggest drug level monitoring. This study was conducted to evaluate the effect of concomitant antiepileptics on levetiracetam plasma concentration in children and to determine the importance of drug plasma concentration in clinical follow-up.

One hundred and forty patients with epileptic seizures on levetiracetam therapy, aged between 1 month and 18 years, were enrolled in this retrospective study. We evaluated gender, age, body weight, daily drug dose, comedication with enzyme inducers and inhibitors, and levetiracetam serum trough concentration records of patients admitted to Pediatric Neurology Clinic between 2018 and 2020.

In this study, 57.9% of 140 patients were on monotherapy. The mean dose of levetiracetam was 35.40 mg/kg/day, while the mean drug concentration was 14.06 μg/mL. The correlation between the dose and the serum concentration in the polytherapy group was poor (P = .024), whereas it was positive and highly significant in the monotherapy group (P < .001). The plasma concentration of the drug was not affected by the enzyme inhibitors and inducers, as there was no significant difference between the groups.

Monitoring is not necessary for patients on levetiracetam, even in polypharmacy. The clinical decision is not affected by plasma drug concentration as drug has linear pharmacokinetics and the drug concentration is not affected by concomitant drugs, and age has no significant impact on plasma concentrations.

Keywords: drug monitoring, epilepsy, levetiracetam, pediatric