Objective: A retrospective study in adult partial epilepsy on the efficacy of lacosamide in relation to previous antiepileptic drug experiences.
Method: We analysed 3-65 months' data on epilepsy-care of 43 pharmacoresistant partial epilepsy patients treated with lacosamide. Further analysis of antiepileptic drug history was carried out in strictly selected subgroups of patients with good and poor therapeutic response to lacosamide (10 and 9 patients, respectively) for 2-10 years long retrospective follow up.
Patients: Adult patients with partial-onset seizures had been treated previously with three or more lifetime antiepileptic drugs without permanent success.
Results: Six patients (14%) were seizure free, eleven patients (25%) have experienced important improvement (their seizure-frequency decreased by at least 50%) for more than 12 months. Fourteen patients (32%) improved for less than 6 months and then have relapsed; and add-on lacosamide proved ineffective in 12 patients (28%). Those selected 10 patients successfully treated with lacosamide (seizure free for at least six months) favourably responded to carbamazepine or oxcarbazepine earlier and levetiracetam was ineffective or even caused worsening. The selected lacosamide-unresponsive nine patients responded unfavourably to carbamazepine or oxcarbazepine earlier. Fifteen patients (35%) suffered side effects as dizziness or sleepiness, in 11 of them lacosamide was combined with a "traditional" sodium-channal blocker antiepileptic drug.
Conclusion: Lacosamide is an effective add-on antiepileptic drug in difficult-to treat adult partial epilepsy patients. Our data suggest that good lacosamide response may be expected in those patients who reacted favourably to "traditional" sodium-channel blocker carbamazepine or oxcarbazepine earlier.