When used for the appropriate seizure type, antiseizure medications (ASMs) are roughly equivalent in efficacy. In addition to the seizure type, the choice of drug is usually based on factors such as ease of use, spectrum of activity, adverse effects, interactions with other drugs, presence of comorbid conditions, suitability for elderly persons and those with childbearing potential, and cost. Treatment should begin with a single drug, increasing the dosage gradually until seizures are controlled or adverse effects become unacceptable. If seizures persist, expert clinicians generally...