The purpose of the trial is to evaluate the safety of intravenous (iv) lacosamide delivered in a single dose followed by 6.5 days of oral lacosamide treatment in subjects with partial-onset seizures.

This multicenter, open-label trial examined safety and tolerability of rapid initiation of adjunctive lacosamide via a single intravenous loading dose followed by oral maintenance treatment in subjects 16 - 60 years of age with partial-onset seizures. Three consecutive 25-subject cohorts were given a progressively increasing dose of lacosamide (200, 300, 400 mg) administered as a single 15-minute intravenous (iv) loading dose followed by the equivalent daily dose administered orally twice daily for 6.5 days with the first oral dose 12 hours after the iv dose. A fourth cohort of 25 subjects repeated the 300 mg dose to provide safety data on a total of 50 subjects at the highest well-tolerated dose.

Inclusion Criteria:

• Diagnosis of epilepsy with simple partial seizures and/or complex partial seizures
• Stable dose regimen of 1 to 2 marketed antiepileptic drug(s) (AED(s)) for 28 days prior to screening and duration of trial
• Acceptable candidate for venipuncture and intravenous (iv) infusion
• At least 1 partial seizure with motor component per 90 days
• Maximum allowed seizure frequency during 28 days prior to screening is 40 partial seizures of any type

Exclusion Criteria:

• Previous use of lacosamide
• History of primary generalized seizures
• History of status epilepticus within last 12 months
• History of cluster seizures during 8 week period prior to screening
• Non-epileptic events, including psychogenic seizures that could be confused with seizures
• Use of neuroleptics, monoamine oxidase (MAO) inhibitors, barbiturates, or narcotic analgesics within 28 days prior to screening
• Received any rescue benzodiazepines more than once during the 28 days prior to screening
• Concomitant treatment of felbamate or previous felbamate therapy within last 6 months
• Prior or concomitant vigabatrin use