Managing Antiepileptic Medication in Dialysis Patients

Abstract

Purpose of review: The purpose of this review is to summarize and discuss available information on the management of epilepsy patients on renal replacement therapy. Older and newer antiepileptic drugs (AEDs) pharmacology will be reviewed, as well as the need to supplement dosages during or after hemodialysis, peritoneal dialysis, and continuous renal replacement treatment.

Recent findings: The great majority of anticonvulsants have been studied in patients with renal failure. Many of them have also been assessed during renal replacement therapy. For some, data are scant, and choice of management must be decided through information on pharmacology. Trials have been conducted in patients with hemodialysis and results have been extrapolated to other types of dialysis. Furthermore, decision on dose supplementation for some of the newer AEDs involves a combination of analysis of the clinical situation and physician expertise. In this paper, we discuss the basis of renal failure and renal replacement therapy as well as antiepileptic pharmacology and the options for dosage replacement during dialysis. Based on pharmacology of each AED, a dosage supplementation is required in cases where there is sufficient clearance of the drug by the method of dialysis chosen. This depends greatly on physicochemical characteristics of the drug: lipophilicity, volume of distribution, protein binding, and molecular weight; and on characteristics of dialysis membrane, mechanism of clearance and blood or dialysate flow. There are studies done for most AEDs in hemodialysis, but more trials are needed in peritoneal dialysis and continuous replacement therapies. There is insufficient information for the newest AEDs, and for some, the recommendation is to simply avoid them in renal failure and dialysis. More studies are necessary in the topic.

Keywords: Antiepileptic; Chronic kidney disease; Dialysis; Epilepsy; Pharmacokinetics; Seizures.