Add-on lacosamide: a retrospective study on the relationship between serum concentration, dosage, and adverse events

Efficacy and Tolerability of Lacosamide in Pediatric and Young Adult Epilepsy Patients with Severe Motor and Intellectual Disabilities

OBJECTIVE

 Epilepsy is common among patients with severe motor and intellectual disabilities (SMID) patients, often taking a prolonged and intractable course. Lacosamide (LCM) is widely used to treat epilepsy in both adults and children. We assess the efficacy and tolerability of LCM among pediatric and young adult epilepsy patients with SMID who suffer from intractable seizures.

METHODS

 This retrospective analysis reviewed the medical records of SMID patients undergoing LCM treatment for more than a year. The study included 24 patients (14 males) aged 3 to 29 years. Epilepsy was classified as focal in 17 patients, generalized in 4 patients, and combined generalized and focal in 3 patients.

RESULTS

 The retention rates were 70.8%, 65%, and 52.9% at 1, 2, and 3 years after LCM initiation, respectively. The 50% responder rate (achieving >50% seizure reduction) for LCM treatment was 50%, with two patients experiencing complete seizure control (absence of seizures for 6 months before the follow-up visit). The 50% responders included a higher proportion of patients with focal epilepsy (58.8%) compared to those with generalized epilepsy (25.0%). Treatment-emergent adverse events (TEAEs) included somnolence in five patients and nausea in two patients. TEAEs, particularly nausea, developed within 1 month after treatment initiation in two patients, leading to LCM discontinuation.

CONCLUSION

 LCM demonstrated good efficacy for intractable epilepsy in pediatric and young adult SMID patients. It was generally well-tolerated, resulting in a favorable retention rate. LCM emerged as a useful antiseizure medication for epilepsy treatment in pediatric and young adult SMID patients.

Effects of CYP2C19 and CYP2C9 polymorphisms on the efficacy and plasma concentration of lacosamide in pediatric patients with epilepsy in China

To evaluate the effects of cytochrome P450 family 2 subfamily C member 9 (CYP2C9) and cytochrome P450 family 2 subfamily C member 19 (CYP2C19) polymorphisms on the plasma concentrations, efficacy, and safety of lacosamide (LCM) among pediatric patients with epilepsy. This prospective study was conducted at two institutions. It included 215 pediatric patients with epilepsy who were under LCM. LCM plasma concentrations were quantified using validated ultra-performance liquid chromatography. CYP2C9 and CYP2C19 polymorphisms were analyzed in all pediatric patients in our hospital's Institute of Clinical Pharmacy research laboratory through polymerase chain reaction, agarose gel electrophoresis detection, gel recovery, and other steps. Seizure frequencies were recorded 3, 6, and 12 months after initiating LCM therapy and compared with the baseline monthly frequency. Clinical information, including efficacy, toxicity, and concomitant drugs, was collected. A total of 158 pediatric patients (73.5%) responded to LCM therapy. Of them, 77 patients reported adverse events while under LCM. The LCM plasma concentration was linearly correlated with its daily dose (r = 0.26, p < 0.001). Patients with adverse events reported higher LCM plasma concentrations (7.9 ± 4.0 µg/mL) than patients without adverse events (6.8 ± 3.0 µg/mL; p < 0.05). The poor metabolizer (PM) group demonstrated the highest concentration-to-dose ratio (1.7 ± 0.7 μg·mL-1·kg·mg-1) than the extensive metabolizer, intermediate metabolizer, and ultra-rapid metabolizer groups (0.8 ± 0.4, 1.0 ± 0.5, and 0.8 ± 0.4 μg·mL-1·kg·mg-1, respectively). The PM group comprised the highest proportion of patients with effective LCM (9/11, 81.8%) and adverse events (7/11, 63.6%).

CONCLUSION

LCM plasma concentrations were strongly associated with its clinical efficacy and toxicity. CYP2C19 polymorphisms affect the plasma concentration and treatment efficacy in pediatric patients with epilepsy. CYP2C19 PMs with two no-function alleles are likely to have higher LCM plasma concentrations.

WHAT IS KNOWN

• LCM is metabolized by CYP2C19, CYP2C9, and CYP3A4 into pharmacologically inactive O-desmethyl-lacosamide; it primarily undergoes renal elimination. • Plasma LCM concentrations in patients treated with the recommended dose vary widely between and within individuals variability.

WHAT IS NEW

• CYP2C19 polymorphisms affect the plasma concentration and treatment efficacy in Chinese pediatric patients with epilepsy. • CYP2C19 PMs with two no-function alleles are likely to have higher plasma LCM concentrations.

Value of drug level concentrations of brivaracetam, lacosamide, and perampanel in care of people with epilepsy

OBJECTIVE

The aim of this study was to determine whether clinical efficacy and reported adverse effects (AEs) of the newer antiseizure medications (ASMs) brivaracetam (BRV), lacosamide (LCM), and perampanel (PER) have been associated with plasma levels of these ASMs. We also investigated whether plasma levels outside the reference range has led to dose adjustments.

METHODS

Plasma levels of 300 people with epilepsy (PWE) seen at our tertiary epilepsy center were determined by liquid chromatography-tandem mass spectrometry. PWE received BRV (n = 100), LCM (n = 100), or PER (n = 100), in most cases in polytherapy. Demographic and clinical data were retrospectively analyzed and related to plasma levels. Clinical efficacy of BRV, LCM, or PER was assessed retrospectively by comparing seizure frequency at the time of current blood draw with seizure frequency at the time of first administration. AEs were also recorded and, if reported, compared retrospectively with the time of first administration.

RESULTS

No significant associations were found between plasma levels of BRV, LCM, or PER and seizure freedom (BRV, p = 1.000; LCM, p = .243; PER, p = .113) or responder status (BRV, p = .118; LCM, p = .478; PER, p = .069) at presentation. There was also no pattern between plasma levels and the occurrence of AEs. In the majority of cases, drug levels outside the reference ranges have not led to adjustments in the daily doses of BRV (93.5%), LCM (93.9%), or PER (89.1%).

SIGNIFICANCE

Plasma levels at a given time point did not allow conclusions to be drawn about seizure control or the occurrence of AEs. Our findings indicate that efficacy and tolerability cannot be predicted based on averaged data from a single plasma measurement due to high interindividual variability. Instead, individual reference values should be established when sufficient clinical data are available, in line with the 2008 International League Against Epilepsy position paper on therapeutic drug monitoring.

Therapeutic drug monitoring of lacosamide among children: is it helpful?

Objective: This study aimed to investigate the efficacy and tolerability of Lacosamide (LCM) in a pediatric population with epilepsy using LCM serum concentration and its correlation to the age of the participants and the dosage of the drug. Methods: Demographic and clinical data were collected from the medical records of children with epilepsy treated with LCM at Shamir Medical Center between February 2019 to September 2021, in whom medication blood levels were measured. Trough serum LCM concentration was measured in the biochemical laboratory using High-Performance Liquid Chromatography (HPLC) and correlated with the administered weight-based medication dosing and clinical report. Results: Forty-two children aged 10.43 ± 5.13 years (range: 1-18) were included in the study. The average daily dose of LCM was 306.62 ± 133.20 mg (range: 100-600). The average number of seizures per day was 3.53 ± 7.25 compared to 0.87 ± 1.40 before and after LCM treatment, respectively. The mean LCM serum concentration was 6.74 ± 3.27 mg/L. No statistically significant association was found between LCM serum levels and the clinical response (p = 0.58), as well as the correlation between LCM dosage and the change in seizure rate (p = 0.30). Our study did not find a correlation between LCM serum concentration and LCM dosage and the gender of the participants: males (n = 17) females (n = 23) (p = 0.31 and p = 0.94, respectively). A positive trend was found between age and LCM serum concentrations (r = 0.26, p = 0.09). Conclusion: Based on the data that has been obtained from our study, it appears that therapeutic drug monitoring for LCM may not be necessary. Nonetheless, further research in this area is needed in the light of the relatively small sample size of the study.

Movement disorders associated with antiseizure medications: A systematic review

New-onset movement disorders have been frequently reported in association with the use of antiseizure medications (ASMs). The frequency of specific motor manifestations and the spectrum of their semiology for various ASMs have not been well characterized. We carried out a systematic review of literature and conducted a search on CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus from inception to April 2021. We compiled the data for all currently available ASMs using the conventional terminology of movement disorders. Among 5123 manuscripts identified by the search, 437 met the inclusion criteria. The largest number of reports of abnormal movements were in association with phenobarbital, valproic acid, lacosamide, and perampanel, and predominantly included tremor and ataxia. The majority of attempted interventions for all agents were discontinuation of the offending drug or dose reduction which led to the resolution of symptoms in most patients. Familiarity with the movement disorder phenomenology previously encountered in relation with specific ASMs facilitates early recognition of adverse effects and timely institution of targeted interventions.

Clinical impact of the dose and blood concentration of lacosamide in Japanese pediatric patients with epilepsy: A cohort study

PURPOSE

The relationship between treatment efficacy/tolerability and the dose/blood concentration of lacosamide (LCM) was investigated in a clinical cohort of Japanese pediatric patients with epilepsy.

METHODS

This retrospective analysis reviewed the medical records of patients treated with LCM for >6 months at the Department of Pediatrics, Hiroshima University Hospital, from September 2017 to January 2021. The collected data included age, sex, epilepsy type, seizure type, seizure frequency before and after treatment initiation, adverse events leading to LCM discontinuation, dose at any evaluation point, serum concentration, and concomitant antiepileptic drugs (AEDs).

RESULTS

The study included 51 patients (31 male patients) between the ages of 2 and 19 years. All patients were Japanese. Epilepsy was classified as focal in 44 patients, generalized in six patients, and combined generalized and focal in one patient. The 50% responder rate for LCM treatment was 56.9%. Seven patients experienced complete seizure control (absence of seizures for 6 months before the follow-up visit). A relationship between dose and blood concentration was identified. Although the blood LCM concentration was higher in the responders than in the nonresponders (7.86 vs. 6.16 μg/mL; p = 0.028), there was no significant difference in dose between the two groups. Lacosamide showed efficacy at a dose >5 mg/kg/day in more than half of the 50% responders. The treatment-emergent adverse events (TEAEs) included seizure aggravation in five patients, irritability in two patients, and somnolence and drug eruption in one patient each. In six patients with TEAEs, the TEAEs developed within 1 month after treatment initiation and led to LCM discontinuation.

CONCLUSION

In Japanese pediatric patients with epilepsy, LCM treatment is effective, particularly at higher doses. The blood concentration may be related more to efficacy than to dose. Lacosamide is generally well-tolerated by pediatric patients, and should be used at the maximum tolerable dose (needed to be gradually increased) in patients with otherwise insufficient seizure control. As TEAEs leading to discontinue treatment likely occur in early phase, it is needed to monitor patients carefully if TEAEs would happen in that phase.

Is Therapeutic Drug Monitoring of Lacosamide Needed in Patients with Seizures and Epilepsy?

Lacosamide is an antiepileptic drug (AED) that has linear pharmacokinetics, predictable blood concentrations, and few drug interactions, setting it apart from other AEDs that require vigorous therapeutic drug monitoring (TDM) such as phenytoin and carbamazepine. However, there have been reports of altered lacosamide pharmacokinetics in some populations. The purpose of this review is to determine whether lacosamide pharmacokinetics are altered in certain patient populations, suggesting the need for TDM. A literature search of Medline, Scopus, Embase, and Cochrane trials was conducted on January 3, 2019 (and then updated on September 2, 2019) to search for articles relevant to the TDM or pharmacokinetics of lacosamide. A total of 56 relevant articles were found and included in this review. Dose of lacosamide is linearly correlated with plasma concentrations and efficacy. However, currently there is no well-established reference range. Overall, the recommended reference ranges varied from 2.2 to 20 mg/L. Lacosamide has very few clinically relevant drug-drug interactions; however, there seems to be a significant drug interaction between lacosamide and enzyme-inducer AEDs. Based on available literature, it appears that lacosamide pharmacokinetics may be altered in severe renal dysfunction, in patients on dialysis and with extremes of age. More evidence is currently needed on lacosamide pharmacokinetics in pregnancy and critical illness. While it is not practical to utilize TDM for all patients, TDM may be useful in patients taking enzyme-inducer AEDs, in patients with decreased renal function or on dialysis, and older adults.

Clinical experience combined with therapeutic drug monitoring of lacosamide

OBJECTIVE

Lacosamide (LCM) is an antiepileptic drug (AED) with insufficient clinical experience in patients with intellectual disability (ID). They often have more severe epilepsy with comorbidities. The objective was to evaluate the efficacy and tolerability of lacosamide (LCM) in patients with refractory epilepsy with and without ID in a real-life setting, taking drug monitoring (TDM) data into account therapeutic.

METHODS

Retrospectively, we identified 344 patients using LCM from the TDM service covering the majority of the country, at the National Center for Epilepsy in Norway (2013-2018). Clinical and TDM data were available for 132 patients.

RESULTS

Forty-four of the 132 patients (33%) had ID. The retention rate was significantly higher in the ID vs the non-ID group after 1 year (84% vs 68%, P < .05). By combining clinical and TDM data, we demonstrated that 37/38 responding patients had serum concentrations above the lower limit of the reference range (>10 µmol/L), and 16/17 with lower concentrations were non-responders. Mean serum concentration/dose ratios were similar in both groups, 0.06 and 0.07 µmol/L/mg. There were no significant differences regarding efficacy and tolerability. The risk of LCM withdrawal was significantly higher when LCM was added to sodium channel blockers, even if the latter was discontinued.

SIGNIFICANCE

Lacosamide was generally well tolerated in patients with drug-resistant epilepsy, where one third had ID, and in these patients the retention rate was higher. The combination of clinical and TDM data could possibly facilitate LCM therapy in these vulnerable patients.

The adverse-effect profile of lacosamide

Introduction: Lacosamide has been used in epilepsy patients in the United States, Europe and Asia since it was approved by the FDA in 2008. Many patients have benefited from this drug as a new generation of sodium channel blocker. With the worldwide use of this drug, its adverse effects have gradually emerged, especially some rare adverse events.Areas covered: The present review aims to summarize the adverse effects of lacosamide reported in the literature in recent years to promote the safe clinical application of the drug.Expert opinion: In more than 10 years of experience in drug usage, adverse reactions of lacosamide have also been gradually discovered. The review showed that lacosamide is safe and effective in antiepileptic treatment, and its common side effects are dizziness, headache, drowsiness, diplopia, and cardiovascular abnormalities. Skin rashes, hematotoxicity and heart damage, psychological symptoms and suicide risk have also been reported and emphasized.

Chronic treatment with the new anticonvulsant drug lacosamide impairs learning and memory processes in rats: A possible role of BDNF/TrkB ligand receptor system

Cognitive impairment is considered a frequent side effect in the drug treatment of epilepsy. The objective of the present study was to investigate the effects of lacosamide (LCM) on learning and memory processes in rats, on the serum level of brain-derived neurotrophic factor (BDNF) and BDNF/TrkB ligand receptor system expression in the hippocampal formation. Male Wistar rats underwent long-term treatment with three different doses of lacosamide - 3 mg/kg (LCM 3), 10 mg/kg (LCM 10) and 30 mg/kg (LCM 30). All rats were subjected to one active and one passive avoidance tests. The BDNF/TrkB immunohistochemical expression in the hippocampus was measured and serum BDNF was determined. The LCM-treated rats made fewer avoidance responses than controls during acquisition training and in the memory retention test. The number of escapes in the LCM 10 and LCM 30 groups decreased throughout the test, while the rats in the LCM 3 group showed fewer escapes only in the memory test in the active avoidance task. In the step-down test, the latency time of the LCM-30 treated rats was reduced as compared with the controls during the learning session and the short- and long-term memory retention tests. Lacosamide induced a dose-dependent reduction of the hippocampal expression of BDNF and its receptor TrkB. We found no significant difference between BDNF serum levels in the test animals and controls. The results of the study suggest that LCM suppresses the learning and memory processes in rats, with the inhibition of hippocampal BDNF/TrkB ligand receptor system being one of the possible mechanisms causing this effect.

Safety and tolerability of lacosamide as adjunctive therapy for adults with partial-onset seizures: Analysis of data pooled from three randomized, double-blind, placebo-controlled clinical trials

OBJECTIVE

The objective of this study was to describe a priori protocol-defined analyses to evaluate the safety and tolerability of adjunctive oral lacosamide (200-600 mg/day) in adults (ages 16-70 years) with partial-onset seizures (POS) using data pooled from three similarly designed randomized, double-blind, placebo-controlled trials (SP667, SP754 [NCT00136019], SP755 [NCT00220415]).

METHODS

Patients with POS (≥2 years' duration, ≥2 previous antiepileptic drugs [AEDs]) uncontrolled by a stable dosing regimen of 1-3 concomitant AEDs were randomized to treatment with lacosamide at doses of 200 mg/day, 400 mg/day, or 600 mg/day, or placebo. Studies comprised a 4- to 6-week titration phase to target dose followed by a 12-week maintenance phase. Safety outcomes included treatment-emergent adverse events (TEAEs) of particular relevance to patients with POS, overall TEAEs, and discontinuations due to TEAEs. Post hoc analyses included evaluation of TEAEs potentially related to cognition and TEAEs leading to discontinuation analyzed by concomitant AEDs.

RESULTS

One thousand three hundred eight patients were randomized to and received treatment; 944 to lacosamide and 364 to placebo. Most patients (84.4%) were taking 2 or 3 concomitant AEDs. The most common drug-associated TEAEs (reported by ≥5% of patients in any lacosamide dose group and with an incidence at least twice that reported for placebo during the treatment phase) were dizziness (30.6% for lacosamide vs 8.2% for placebo), nausea (11.4% vs 4.4%), and diplopia (10.5% vs 1.9%). Common drug-associated TEAEs generally appeared to be dose-related, and the incidence of each was lower during the 12-week maintenance phase than during the titration phase. Most TEAEs were either mild or moderate in intensity; severe TEAEs were predominantly observed with lacosamide 600 mg/day. No individual serious TEAE occurred in ≥1% of all lacosamide-treated patients. Treatment-emergent adverse events led to discontinuation in 8.1%, 17.2%, and 28.6% of the lacosamide 200-, 400-, and 600-mg/day groups, respectively (vs 4.9% of placebo). Few TEAEs were related to rash, weight loss/gain, changes in clinical chemistry parameters, or psychiatric disturbances, or were seizure-related. The odds of reporting any potential cognition-related TEAE vs placebo increased with dose and were similar between lacosamide doses of 200 and 400mg/day and placebo (odds ratio 1.3, 95% confidence interval 0.7-2.4). Discontinuations due to TEAEs based on most commonly used AEDs taken in combination with lacosamide (all doses combined) were carbamazepine (15.3% [51/334] vs 3.9% [5/129] placebo), lamotrigine (19.2% [56/291] vs 4.3% [5/117]), and levetiracetam (10.1% [28/278] vs 3.9% [4/103]).

CONCLUSIONS

The safety and tolerability profile of adjunctive lacosamide in this detailed evaluation was similar to that observed in the individual double-blind trials. Adjunctive lacosamide was associated with TEAEs related to the nervous system and gastrointestinal tract, predominantly during titration.

Lacosamide: a review of its use as adjunctive therapy in the management of partial-onset seizures

Lacosamide (Vimpat(®)) is a functionalized amino acid available orally (as a syrup or tablet) and as an intravenous infusion. It is believed to exert its antiepileptic effect by selectively enhancing the slow inactivation of voltage-gated sodium channels. Lacosamide is approved in several countries worldwide as an adjunctive therapy for the treatment of partial-onset seizures; however, prescribing regulations differ between countries. This article reviews the use of lacosamide as indicated in adults and adolescents (aged 16-18 years) in the EU, where it is approved in this patient population as an adjunctive therapy to other AEDs in the treatment of partial-onset seizures, with or without secondary generalization. In three randomized, double-blind, placebo-controlled, multicentre studies in adults and adolescents (aged 16-18 years) with partial-onset seizures, adjunctive therapy with oral lacosamide (administered for an initial titration period followed by 12 weeks' maintenance therapy) generally reduced the frequency of seizures to a significantly greater extent than placebo, with antiepileptic efficacy sustained following longer-term treatment (up to 8 years) in this patient population. Oral and intravenous lacosamide were generally well tolerated in clinical studies, with the majority of adverse events being mild or moderate in severity. Very common adverse reactions following adjunctive therapy with oral lacosamide included diplopia, dizziness, headache and nausea; the tolerability profile of intravenous lacosamide appeared consistent with that of oral lacosamide, although intravenous administration was associated with local adverse events, such as injection site discomfort or pain, irritation and erythema. Thus, oral and intravenous lacosamide as an adjunctive therapy to other AEDs provides a useful option in the treatment of patients with partial-onset seizures.

Development of lacosamide for the treatment of partial-onset seizures

Lacosamide is an antiepileptic drug (AED) available in multiple formulations that was first approved in 2008 as adjunctive therapy for partial-onset seizures (POS) in adults. Unlike traditional sodium channel blockers affecting fast inactivation, lacosamide selectively enhances sodium channel slow inactivation. This mechanism of action results in stabilization of hyperexcitable neuronal membranes, inhibition of neuronal firing, and reduction in long-term channel availability without affecting physiological function. Lacosamide has a well-characterized and favorable pharmacokinetic profile, including a fast absorption rate, minimal or no interaction with cytochrome P-450 izoenzymes, and a low potential for drug-drug interactions. Lacosamide clinical development included three placebo-controlled, double-blind, randomized trials conducted in more than 1300 patients, each demonstrating safety and efficacy of lacosamide compared to placebo as adjunctive therapy for adults with POS. The clinical use of lacosamide may broaden, pending results of trials evaluating its use as monotherapy for POS in adults, as treatment for epilepsy in pediatric subjects, and as adjunctive treatment for uncontrolled primary generalized tonic-clonic seizures in those with idiopathic generalized epilepsy.