Safety & pK of IV loading dose of lacosamide in the ICU

Efficacy of lacosamide and phenytoin in status epilepticus: A systematic review

OBJECTIVES

To compare the evidence on efficacy, safety, tolerability, and impact on short term/long functional outcome of lacosamide (LCM) and phenytoin (PHT) in patients with status epilepticus.

MATERIALS & METHODS

We conducted a systematic literature search of relevant electronic databases using a suitable search strategy to identify studies directly comparing PHT and LCM, irrespective of dose and duration in patients with convulsive and/or nonconvulsive status epilepticus (SE). We used a standardized assessment form to extract information on the study design, data sources, methodologic framework, efficacy, and adverse events attributed to PHT and LCM from included studies and compared the efficacy and safety outcomes, using a fixed/random effect model.

RESULTS

Five studies were found to be eligible for inclusion out of 192 search items, enrolling a total of 115 and 166 participants (predominantly with SE) in LCM and PHT arm, respectively. Baseline characteristics were comparable between both arms. The proportion with seizure control was comparable between both arms (57.3% in LCM vs. 45.7% in PHT arm, p = 0.28) and even in the subgroup analysis separately for convulsive and non-convulsive SE. Proportion with treatment-emergent adverse events (TEAE) were comparable in both (17.6% vs. 12.2%, p = 0.20), but serious adverse events (SAE) were higher in PHT arm (5.1% vs. 0.8%, p = 0.049). The proportion with all-cause mortality and survival with moderate-severe disability were comparable between both arms (p = 0.23 and 0.37, respectively).

CONCLUSION

LCM has comparable efficacy with fewer SAEs as compared to PHT for achieving seizure control in patients with SE.

Intravenous Lacosamide in Seizure Clusters: Dose and Efficacy

PURPOSE

The objective of our study was to evaluate the relationship between the loading dose and efficacy of lacosamide (LCM), when used in seizure clusters (SCs).

METHODS

A cohort of patients with SC treated with intravenous (IV)-LCM between September 2017 and September 2019 was retrospectively examined. Demographic data, type of seizure emergency, etiology, response rate, previous oral antiepileptic drugs used, total LCM loading dose, and side effects were reviewed.

RESULTS

Thirty-nine cases of epileptic emergencies treated with IV LCM were collected. The mean age was 59.25 years (18-88 years), and the median loading dose was 136.5 mg (100-300 mg) with a response rate in the whole population of 29.2%. Nine patients received a loading dose of 200 to 300 mg, and their response rate was 89%. Common side effects (drowsiness and dizziness) were mild. No electrocardiogram changes or other cardiovascular side effects, or unexpected side effects were seen.

CONCLUSIONS

In adults with SC, a loading dose of IV LCM of 200 mg or more achieved 89% response rate in this cohort. Loading doses of less than 300 mg caused mild side effects only.

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.

Safety, tolerability, and pharmacokinetics of weight-based IV loading dose of lacosamide in the ICU

Among the newer antiseizure medications, lacosamide (LCM) has been increasingly used for acute seizures and status epilepticus in intensive care unit (ICU). We reviewed retrospectively weight-based dosing of IV LCM in patients admitted to ICU with acute seizures and status epilepticus. We have analyzed 354/382 patient treated with IV LCM in ICU during the years 2013-2016. Data collected were age, total body weight, body mass index (BMI), loading dose, post-IV infusion LCM blood level, duration of infusion, blood pressure, heart rate, oxygen saturation, mean arterial pressures, and documented initiation of pressor agents during or within in 30 min of infusion. Larger doses >8 mg/kg of IV LCM that can be safely administered in ICU patients produce effective plasma levels of 15-20 μg/ml with relatively constant volume of distribution.

Antiepileptic Drug Therapy for Status Epilepticus

Status epilepticus (SE) is one of the most serious neurologic emergencies. SE is a condition that encompasses a broad range of semiologic subtypes and heterogeneous etiologies. The treatment of SE primarily involves the management of the underlying etiology and the use of antiepileptic drug therapy to rapidly terminate seizure activities. The Drug Committee of the Korean Epilepsy Society performed a review of existing guidelines and literature with the aim of providing practical recommendations for antiepileptic drug therapy. This article is one of a series of review articles by the Drug Committee and it summarizes staged antiepileptic drug therapy for SE. While evidence of good quality supports the use of benzodiazepines as the first-line treatment of SE, such evidence informing the administration of second- or third-line treatments is lacking; hence, the recommendations presented herein concerning the treatment of established and refractory SE are based on case series and expert opinions. The choice of antiepileptic drugs in each stage should consider the characteristics and circumstances of each patient, as well as their estimated benefit and risk to them. In tandem with the antiepileptic drug therapy, careful searching for and treatment of the underlying etiology are required.

Treatment of Refractory Convulsive Status Epilepticus: A Comprehensive Review by the American Epilepsy Society Treatments Committee

Purpose:

Established tonic–clonic status epilepticus (SE) does not stop in one-third of patients when treated with an intravenous (IV) benzodiazepine bolus followed by a loading dose of a second antiseizure medication (ASM). These patients have refractory status epilepticus (RSE) and a high risk of morbidity and death. For patients with convulsive refractory status epilepticus (CRSE), we sought to determine the strength of evidence for 8 parenteral ASMs used as third-line treatment in stopping clinical CRSE.

Methods:

A structured literature search (MEDLINE, Embase, CENTRAL, CINAHL) was performed to identify original studies on the treatment of CRSE in children and adults using IV brivaracetam, ketamine, lacosamide, levetiracetam (LEV), midazolam (MDZ), pentobarbital (PTB; and thiopental), propofol (PRO), and valproic acid (VPA). Adrenocorticotropic hormone (ACTH), corticosteroids, intravenous immunoglobulin (IVIg), magnesium sulfate, and pyridoxine were added to determine the effectiveness in treating hard-to-control seizures in special circumstances. Studies were evaluated by predefined criteria and were classified by strength of evidence in stopping clinical CRSE (either as the last ASM added or compared to another ASM) according to the 2017 American Academy of Neurology process.

Results:

No studies exist on the use of ACTH, corticosteroids, or IVIg for the treatment of CRSE. Small series and case reports exist on the use of these agents in the treatment of RSE of suspected immune etiology, severe epileptic encephalopathies, and rare epilepsy syndromes. For adults with CRSE, insufficient evidence exists on the effectiveness of brivaracetam (level U; 4 class IV studies). For children and adults with CRSE, insufficient evidence exists on the effectiveness of ketamine (level U; 25 class IV studies). For children and adults with CRSE, it is possible that lacosamide is effective at stopping RSE (level C; 2 class III, 14 class IV studies). For children with CRSE, insufficient evidence exists that LEV and VPA are equally effective (level U, 1 class III study). For adults with CRSE, insufficient evidence exists to support the effectiveness of LEV (level U; 2 class IV studies). Magnesium sulfate may be effective in the treatment of eclampsia, but there are only case reports of its use for CRSE. For children with CRSE, insufficient evidence exists to support either that MDZ and diazepam infusions are equally effective (level U; 1 class III study) or that MDZ infusion and PTB are equally effective (level U; 1 class III study). For adults with CRSE, insufficient evidence exists to support either that MDZ infusion and PRO are equally effective (level U; 1 class III study) or that low-dose and high-dose MDZ infusions are equally effective (level U; 1 class III study). For children and adults with CRSE, insufficient evidence exists to support that MDZ is effective as the last drug added (level U; 29 class IV studies). For adults with CRSE, insufficient evidence exists to support that PTB and PRO are equally effective (level U; 1 class III study). For adults and children with CRSE, insufficient evidence exists to support that PTB is effective as the last ASM added (level U; 42 class IV studies). For CRSE, insufficient evidence exists to support that PRO is effective as the last ASM used (level U; 26 class IV studies). No pediatric-only studies exist on the use of PRO for CRSE, and many guidelines do not recommend its use in children aged <16 years. Pyridoxine-dependent and pyridoxine-responsive epilepsies should be considered in children presenting between birth and age 3 years with refractory seizures and no imaging lesion or other acquired cause of seizures. For children with CRSE, insufficient evidence exists that VPA and diazepam infusion are equally effective (level U, 1 class III study). No class I to III studies have been reported in adults treated with VPA for CRSE. In comparison, for children and adults with established convulsive SE (ie, not RSE), after an initial benzodiazepine, it is likely that loading doses of LEV 60 mg/kg, VPA 40 mg/kg, and fosphenytoin 20 mg PE/kg are equally effective at stopping SE (level B, 1 class I study).

Conclusions:

Mostly insufficient evidence exists on the efficacy of stopping clinical CRSE using brivaracetam, lacosamide, LEV, valproate, ketamine, MDZ, PTB, and PRO either as the last ASM or compared to others of these drugs. Adrenocorticotropic hormone, IVIg, corticosteroids, magnesium sulfate, and pyridoxine have been used in special situations but have not been studied for CRSE. For the treatment of established convulsive SE (ie, not RSE), LEV, VPA, and fosphenytoin are likely equally effective, but whether this is also true for CRSE is unknown. Triple-masked, randomized controlled trials are needed to compare the effectiveness of parenteral anesthetizing and nonanesthetizing ASMs in the treatment of CRSE.

New anti-seizure medication for elderly epileptic patients

Introduction: Epilepsy treatment in older people requires specific consideration owing to more physical co-morbidities, the risk of drug-to-drug interactions through polypharmacy, and differences in pharmacodynamics and pharmacokinetics. There are many 'newer' antiepileptic drugs (AEDs) widely used for various seizure types and seizure disorders. However, there is limited specific evidence for the efficacy, safety, and tolerability of these treatments in the elderly population. Areas covered: This review summarises the current most robust evidence available for the use of the newer AEDs belonging to generation two and three in elderly people with epilepsy. The article provides practical evidenced based clinical information to help prescribers choose the most appropriate AED from the drugs discussed. Expert opinion: Diagnosing new onset epilepsy in the elderly population requires specialist assessment. Treatment plans need to be tailored to accommodate an individual's co-morbidities, concurrent medications, and general health status. To date, few clinical investigations consider the elderly population specifically despite the increased risk factors. There is a need for large quality trial data to assess the impact of the newest AEDs on seizure control and quality of life in this population with complex needs.

Intravenous lacosamide (LCM) in status epilepticus (SE): Weight-adjusted dose and efficacy

BACKGROUND

Some studies suggest higher efficacy of lacosamide (LCM) in status epilepticus (SE) with higher loading doses; however, this weight-adjusted dose has not been evaluated.

OBJECTIVE

The objective was to evaluate the relationship between loading weight-adjusted dose and efficacy of LCM in SE.

METHODS

A group of patients with SE treated with LCM from Spanish hospitals was examined retrospectively. Demographic data, type of SE, etiology, response rate, last antiepileptic drug (AED) used, treatment line in which LCM was used, total loading dose, and weight-adjusted dose were collected.

RESULTS

One hundred sixty-five cases of SE were collected; 87 (52.7%) patients had nonconvulsive SE. Mean age was 64.2 ± 17.2 and 60.6% (n = 100) were men. Regarding etiology, SE was considered as acute symptomatic in 85 (51.5%), remote symptomatic in 51 (30.9%), progressive symptomatic in 10 (6.1%), and cryptogenic in 19 (11.5%). Lacosamide was used as the third drug in 46.1%, and as a second option in 28%. In 115 patients, clonazepam had been used as the first option, and no benzodiazepines had been administered in the remaining 50. The median loading dose was 400 mg (100-600 mg), and the weight-adjusted dose was 5 mg/kg (3-6 mg/kg). The response rate was 63.3%, and 55.1% responded within the first 12 h. Efficacy was significantly higher in patients who had taken benzodiazepines at LCM loading doses >5.3 mg/kg (p = 0.006). This relationship was maintained independent of using other concomitant AEDs. However, if benzodiazepines were not taken, this relationship was not found.

CONCLUSIONS

In adults with benzodiazepine-resistant SE, the response rate to LCM was higher, with weight-adjusted doses above 5.3 mg/kg.

Clinical management of elderly patients with epilepsy; the use of lacosamide in a single center setting

INTRODUCTION

Lacosamide (LCM) is a third-generation antiepileptic drug (AED) for which there is limited experience in the treatment of elderly patients with epilepsy. This study was performed to evaluate the use of LCM in this particular patient group, focusing on its tolerability and effectiveness. This is a retrospective, single-center study, in patients over 60years old treated with LCM between 1/2010 and 5/2015. Altogether, 233 elderly patients receiving LCM were identified; of these, 67 fulfilled the inclusion criteria, i.e., LCM administered for at least 2weeks.

RESULTS

Lacosamide was initiated for acute seizure disorders (prolonged complex partial seizures, recurrent seizures, or status epilepticus) in 54 patients (81%) and for chronic epilepsy in 13 patients in an outpatient setting. The mean follow-up period for LCM treatment was 14months. The mean daily dose of LCM at the end of follow-up was 368mg (range: 100-600) for those 57 patients that continued treatment. Ten patients (15%) stopped LCM treatment but none because of lack of efficacy and only three patients (4%) because of side effects. The most frequent side effects were dizziness, fatigue, and tremor.

CONCLUSIONS

Lacosamide was well tolerated even at relatively high doses and in combination therapy.

Intravenous lacosamide in status epilepticus: Correlation between loading dose, serum levels, and clinical response

INTRODUCTION

Intravenous lacosamide (LCM) is increasingly used in the treatment of status epilepticus (SE), but optimal loading dose and target serum levels are unclear. We analysed the correlation between LCM serum levels after intravenous loading dose and clinical response.

MATERIALS AND METHODS

Retrospective study in two centres from December 2014 to May 2016 including consecutive SE patients treated with LCM, in which trough serum levels after intravenous loading dose were available. Trough levels were correlated with the loading dose and the clinical response, defined as LCM introduction terminating SE without the need of further treatment. Correlations were adjusted for other SE characteristics.

RESULTS

Among 40 patients, 16 (40%) responded to LCM. LCM serum concentrations within the reference interval (10-20mg/l) were associated with loading doses of >9mg/kg (p=0.003; χ2). However, we observed no difference between LCM serum levels in responders (median 10.4mg/l) versus non-responders (median 9.5mg/l; p=0.36; U test), even after adjusting for other predictors of clinical outcome (SE severity, aetiology, and number of previous treatment).

DISCUSSION

High intravenous LCM loading doses (>9mg/kg) were associated with serum levels within the reference interval, there was however no correlation with the clinical response. Prospective studies are needed to evaluate the benefit of increasing the LCM loading dose in SE.

Lacosamide in status epilepticus: Systematic review of current evidence

OBJECTIVE

The intravenous formulation of lacosamide (LCM) and its good overall tolerability and safety favor the use in status epilepticus (SE). The aim of this systematic review was to identify and evaluate studies reporting on the use of LCM in SE.

METHODS

We performed a systematic literature search of electronic databases using a combined search strategy from 2008 until October 2016. Using a standardized assessment form, information on the study design, methodologic framework, data sources, efficacy, and adverse events attributed to LCM were extracted from each publication and systematically reported.

RESULTS

In total, 522 SE episodes (51.7% female) in 486 adults and 36 children and adolescents were evaluated with an overall LCM efficacy of 57%. Efficacy was comparable between use in nonconvulsive (57%; 82/145) and generalized-convulsive (61%; 30/49; p = 0.68) SE, whereas overall success rate was better in focal motor SE (92%; 34/39, p = 0.013; p < 0.001). The efficacy with later positioning of LCM decreased from 100% to 20%. The main adverse events during treatment of SE are dizziness, abnormal vision, diplopia, and ataxia. Overall, lacosamide is well tolerated and has no clinically relevant drug-drug interactions.

SIGNIFICANCE

The available data regarding the use of LCM in SE are promising, with a success rate of 57%. The strength of LCM is the lack of interaction potential and the option for intravenous use in emergency situations requiring rapid uptitration.