Pros and Cons of Extended-Release Antiepileptic Drugs

Andrew N. Wilner, MD


February 17, 2016

In This Article


The choice of an AED must be individualized for each patient, taking into account such factors as patient age, comorbidities, seizure type, epilepsy syndrome, adverse events, genetic profile, formulation (liquid, tablet, capsule, sprinkle), insurance coverage, and medication cost.

A choice must also be made between IR and ER preparations, and sometimes between different ER preparations. Pharmacokinetic modeling by Pellock and Brittain[4] suggests that patients may benefit from ER products without necessarily suffering a larger drop in serum level compared with an IR product after a missed dose. More detailed in vivo comparative studies between ER and IR products that include seizure counts, adverse effects, and serum levels would fortify their argument.

Nonetheless, ER preparations offer the possibility of improved tolerability, more stable serum levels, and enhanced adherence and should be considered for appropriate patients. In addition, all patients with epilepsy should be educated regarding the importance of not missing a dose, whether they are taking an IR or ER product.