Lacosamide: An Adjunctive Agent for Partial-Onset Seizures and Potential Therapy for Neuropathic Pain

Abstract

Objective: To review the pharmacology, pharmacokinetics, efficacy, and safety of lacosamide, a new agent for use as adjunctive treatment in partial-onset seizures and a potential agent for treatment of neuropathic pain. Data Sources: A MEDLINE search (1966–July 2009) was conducted using the key words lacosamide, harkoseride, SPM-927, ADD-234037, epilepsy, anticonvulsant, and neuropathic pain. Bibliographies of all articles retrieved were also reviewed. Study Selection and Data Extraction: All studies including humans and published in English with data describing lacosamide for the adjunctive treatment of partial-onset seizures and for treatment of neuropathic pain were reviewed. Data Synthesis: Lacosamide is a functionalized amino acid molecule that selectively enhances the slow inactivation of voltage-gated sodium channels and interacts with the collapsin-response mediator protein-2. With its bioavailability of approximately 100%, minimal protein binding, and few drug–drug interactions, lacosamide has a favorable pharmacokinetic profile. Recent data suggest that lacosamide may have a role as adjunctive treatment of partial-onset seizures. Open-label studies showed a 14-47% reduction in seizure frequency, while placebo-controlled trials demonstrated a 26-40% reduction in seizure frequency. The 50% responder rates ranged from 32.7% to 41.2% with varying doses of lacosamide. Although lacosamide use is not approved by the Food and Drug Administration for treatment of neuropathic pain, studies demonstrated reductions of 2.01–3.60 in pain scale scores. The most common adverse effects, occurring in greater than 10% of subjects in the clinical trials, include arthralgia, ataxia, blurred vision, diplopia, dizziness, fatigue, headache, injection site pain (only in intravenous studies), nausea, tremor, upper respiratory tract infection, and vomiting. Conclusions: Lacosamide is an effective agent for adjunctive treatment of refractory partial-onset seizures. Its exact role in the treatment of neuropathic pain needs to be determined.