Genetic variation in dopaminergic activity is associated with the risk for psychiatric side effects of levetiracetam

Abstract

Levetiracetam (LEV) is a highly effective antiepileptic agent. A clinically relevant psychiatric complication of LEV treatment, however, is the provocation of irritability and aggression. Recent behavioral research indicates that personality traits may predispose to these side effects. To assess the genetic basis of the adverse psychotropic profile of LEV, a candidate gene-based two-stage association study was conducted. Polymorphisms were a priori selected according to their relevance for impulsivity and reactive-impulsive aggression. Based on data from both stages, a Bonferroni-corrected joint meta-analysis was computed. Stage 1 analysis included 290 patients with epilepsy and revealed a higher load of adverse psychotropic side effects of LEV in patients carrying genetic variants associated with decreased dopaminergic activity: rs1611115 (dopamine-β-hydroxylase, DBH), rs4680 (catechol-O-methyltransferase, COMT), and rs1800497 (dopamine receptor D2-associated ANKK1 TAQ-1A). Stage II analysis including 100 patients with epilepsy, and joint meta-analysis confirmed the effect of the rs1800497 polymorphism (Bonferroni corrected significance of the joint meta-analysis, p = 0.0096). Confirming the suggestion from behavioral observations that patients might be predisposed to develop irritation and aggression under treatment with LEV, the findings provide first evidence of an association of genetic variation in dopaminergic activity and the risk for psychiatric complications of LEV treatment. Replication and further work is required to prove a true causal relationship. Overall, the pharmacogenomic approach to behavioral side effects may provide a future tool to predict adverse psychotropic effects related to antiepileptic drugs.