Lacosamide retention rate comparable to other antiepileptic drugs
The retention rate of lacosamide (LCM) treatment in patients with epilepsy and intellectual disabilities is similar to that of other previously investigated antiepileptic drugs (AEDs), a study has shown. Moreover, LCM retention rate is influenced by the number of background AEDs but not concomitant sodium channel blocker (SCB) use.
The high rate of drug resistance is considered one of the major challenges in medically caring for patients with epilepsy and intellectual disabilities, and a lack of evidence-based information about the efficacy and tolerability of AEDs in this population makes the situation worse, researchers said.
In the present monocentric, observational study, researchers evaluated LCM retention rates and the impact of therapy-related variables on the long-term retention of LCM. The population comprised 136 patients aged 2 to 66 years (mean, 32.7 years) with intellectual disabilities and drug-resistant epilepsy. Majority of the patients were female and had focal epilepsy.
Mean LCM dosage in the cohort was 411 mg, and the most commonly selected LCM dosage was 400 mg/day (45 percent). About one-third of the patients initiated LCM as add-on polytherapy, whereas two-thirds had another AED withdrawn before LCM was initiated.
LCM retention rates were 62 percent at 1 year, 43.7 percent at 2 years, and 29.1 percent at 3 and 4 years. Insufficient therapeutic benefits (69 percent) was the most frequently reported reason for LCM discontinuation, followed by adverse events (11 percent) and a combination of both factors (8 percent).
Kaplan-Meier analysis showed that the number of concurrent AEDs had a notably negative effect on long-term LCM retention rates. An additional and independent impact of concomitant SCB therapy on retention rate could not be confirmed.
“It has been shown that concomitant SCB use is a key factor in increasing the risk of LCM failure in children with epilepsy. This finding has not been replicated in our predominantly adult sample of patients with IDs,” researchers said.
LCM was originally licensed as an add-on AED for adults aged ≥16 years with focal epilepsy either with or without secondary generalized seizures. Pooled analysis of previous trials demonstrate that the drug provides additional efficacy when combined with a broad range of AEDs and is generally well tolerated. [CNS Drugs 2010;24:1055–1068; Epilepsia 2015;56:1921–1930; Epilepsy Res 2012;98:260–263]