Lacosamide (Vimpat®) is a functionalized amino acid available orally (as a solution or tablets) and as an intravenous infusion for use as monotherapy (only in the USA) or adjunctive therapy for the treatment of focal seizures in adult and adolescent (aged ≥17 years in the USA) patients with epilepsy. As adjunctive therapy to other antiepileptic drugs (AEDs), lacosamide provided effective seizure control and was generally well tolerated in adults and adolescents (aged ≥16 years) in randomized clinical trials and in the real-world setting. In clinical trials, adjunctive lacosamide provided significantly greater reductions in 28-day seizure rates than adjunctive placebo, with these benefits maintained after up to 8 years of therapy in open-label extension studies. Moreover, patients were effectively switched from oral to short-term intravenous adjunctive therapy at the same dosage, which may be particularly beneficial in situations where oral therapy is not suitable. Conversion to lacosamide monotherapy was superior to a historical-control cohort in patients with focal seizures converting from previous AED therapy. In the absence of head-to-head comparisons with other AEDs, the exact position of lacosamide relative to other AEDs remains to be fully determined. In the meantime, oral and intravenous lacosamide provides a useful option as monotherapy (only in the USA) or adjunctive therapy for the treatment of focal seizures in adult and adolescent (aged ≥17 years in the USA) patients with epilepsy.