Placebo-controlled study of the efficacy and safety of lamotrigine in patients with partial seizures. U.S. Lamotrigine Protocol 0.5 Clinical Trial Group

Efficacy and safety of add-on antiseizure medications for focal epilepsy: A network meta-analysis

OBJECTIVE

Several antiseizure medications (ASMs) have been approved for the treatment of focal epilepsy. However, there is a paucity of evidence on direct comparison of ASMs. We evaluated the comparative efficacy and safety of all approved add-on ASMs for the treatment of focal epilepsy using network meta-analysis.

METHODS

Data through extensive literature search was retrieved from PubMed, Embase, Cochrane, and ClinicalTrial.gov databases using predefined search terms from inception through March 2023. PRISMA reporting guidelines (CRD42023403450) were followed in this study. Efficacy outcomes assessed were ≥50%, ≥75%, and 100% responder rates. Patient retention rate and safety outcomes such as overall treatment-emergent adverse events (TEAEs) and individual TEAEs were assessed. "Gemtc" 4.0.4 package was used to perform Bayesian analysis. Outcomes are reported as relative risks (RRs) and 95% confidence interval (CI).

RESULTS

Literature search retrieved 5807 studies of which, 75 studies were included in the analysis. All ASMs showed significantly higher ≥50% responder rate compared with placebo. Except the ≥75% seizure frequency reduction for zonisamide (2.23; 95% CI: 1.00-5.70) and 100% for rufinamide (2.03; 95% CI: 0.54-11.00), all other interventions showed significantly higher ≥75% and 100% responder rates compared with placebo. Among treatments, significantly higher 100% responder rate was observed with cenobamate compared to eslicarbazepine (10.71; 95% CI: 1.56-323.9) and zonisamide (10.63; 95% CI: 1.37-261.2). All ASMs showed a lower patient retention rate compared to placebo, with the least significant value observed for oxcarbazepine (0.77; 95% CI: 0.7-0.84). Levetiracetam showed a lower risk of incidence (1.0; 95%CI: 0.94-1.1; SUCRA: 0.885067) for overall TEAE compared with other medications.

SIGNIFICANCE

All approved ASMs were effective as add-on treatment for focal epilepsy. Of the ASMs included, cenobamate had the greatest likelihood of allowing patients to attain seizure freedom.

PLAIN LANGUAGE SUMMARY

This article compares the efficacy and safety of antiseizure medications (ASMs) currently available to neurologists in the treatment of epileptic patients. Several newer generation ASMs that have been developed may be as effective or better than the older medications. We included 75 studies in the analysis. In comparison, all drugs improved ≥50%, ≥75% and 100% responder rates compared to control, except for Zonisamide and Rufinamide in the ≥75% and 100% responder rate categories. Retention of patients undergoing treatment was lower in drugs than placebo. All drugs were tolerated, the levetiracetam showed the best tolerability. Cenobamate more likely help completely to reduce seizures.

Lamotrigine add-on therapy for drug-resistant focal epilepsy

BACKGROUND

This is an updated version of a Cochrane Review last updated in 2020. Epilepsy is a common neurological disorder, affecting 0.5% to 1% of the population. In nearly 30% of cases, epilepsy is resistant to currently available drugs. Pharmacological treatment remains the first choice to control epilepsy. Lamotrigine is a second-generation antiseizure medication. When used as an add-on (in combination with other antiseizure medications), lamotrigine can reduce seizures, but with some adverse effects.

OBJECTIVES

To evaluate the benefits and harms of add-on lamotrigine, compared with add-on placebo or no add-on treatment in people with drug-resistant focal epilepsy.

SEARCH METHODS

For this update, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid) on 3 October 2022 with no language restrictions. CRS Web includes randomised and quasi-randomised controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialised Registers of Cochrane Review Groups, including Epilepsy.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that investigated add-on lamotrigine versus add-on placebo or no add-on treatment in people of any age with drug-resistant focal epilepsy. We used data from the first period of eligible cross-over trials.

DATA COLLECTION AND ANALYSIS

For this update, two review authors independently selected trials and extracted data. Our primary outcome was 50% or greater reduction in seizure frequency. Our secondary outcomes were treatment withdrawal, adverse effects, cognitive effects, and quality of life. Primary analyses were by intention-to-treat. We performed sensitivity best- and worse-case analyses to account for missing outcome data. We calculated pooled risk ratios (RRs) with 95% confidence intervals (95% Cls) for dichotomous outcomes.

MAIN RESULTS

We identified no new studies for this update, so the results and conclusions of the review are unchanged. We included five parallel-group studies in adults or children, eight cross-over studies in adults or children, and one parallel study with a responder-enriched design in infants. In total, these 14 studies enroled 1806 eligible participants (38 infants, 199 children, 1569 adults). Baseline phases ranged from four to 12 weeks and treatment phases ranged from eight to 36 weeks. We rated 11 studies (1243 participants) at low overall risk of bias and three (697 participants) at unclear overall risk of bias due to lack of information on study design. Four studies (563 participants) reported effective blinding. Lamotrigine compared with placebo probably increases the likelihood of achieving 50% or greater reduction in seizure frequency (RR 1.80, 95% CI 1.45 to 2.23; 12 trials, 1322 participants (adults and children); moderate-certainty evidence). There is probably little or no difference in risk of treatment withdrawal for any reason among people treated with lamotrigine versus people treated with placebo (RR 1.11, 95% CI 0.91 to 1.37; 14 trials; 1806 participants; moderate-certainty evidence). Lamotrigine compared with placebo is probably associated with a greater risk of ataxia (RR 3.34, 99% Cl 2.01 to 5.55; 12 trials; 1525 participants; moderate-certainty evidence), dizziness (RR 1.76, 99% Cl 1.28 to 2.43; 13 trials; 1768 participants; moderate-certainty evidence), nausea (RR 1.81, 99% CI 1.22 to 2.68; 12 studies, 1486 participants; moderate-certainty evidence), and diplopia (RR 3.79, 99% Cl 2.15 to 6.68; 3 trials, 944 participants; moderate-certainty evidence). There is probably little or no difference in the risk of fatigue between lamotrigine and placebo (RR 0.82, 99% CI 0.55 to 1.22; 12 studies, 1552 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Lamotrigine as an add-on treatment for drug-resistant focal seizures is probably effective for reducing seizure frequency. Certain adverse effects (ataxia, dizziness, diplopia, and nausea) are probably more likely to occur with lamotrigine compared with placebo. There is probably little or no difference in the number of people who withdraw from treatment with lamotrigine versus placebo. The trials were of relatively short duration and provided no long-term evidence. In addition, some trials had few participants. Further trials are needed to assess the long-term effects of lamotrigine and to compare lamotrigine with other add-on drugs.

Efficacy and Safety of Five Broad-Spectrum Antiseizure Medications for Adjunctive Treatment of Refractory Epilepsy: A Systematic Review and Network Meta-analysis

BACKGROUND

Overall, up to one-third of epilepsy patients have drug-resistant epilepsy. However, there was previously no meta-analysis to support the guidelines for broad-spectrum antiseizure medication selection for the adjunctive treatment of refractory epilepsy. In the present meta-analysis, we assessed the efficacy and safety of three second-generation broad-spectrum antiseizure medications, lamotrigine (LTG), levetiracetam (LEV), and topiramate (TPM), and two third-generation broad-spectrum antiseizure medications, perampanel (PER) and lacosamide (LCM), for the adjunctive treatment of refractory epilepsy.

METHODS

We systematically searched PubMed, Embase, and CENTRAL from inception to July 15, 2022. The studies included in the meta-analysis were required to meet the following criteria: (1) be randomized, double-blind clinical trials; (2) include patients aged >2 years with a clinical diagnosis of drug-resistant epilepsy; (3) have at least 8 weeks for the treatment period excluding the titration phase; and (4) report the outcomes of seizure response, seizure freedom and the withdrawal rate due to treatment-emergent adverse effects. Data were extracted, and the risk of bias for each study was assessed by two authors independently using RoB2 tools. We performed the network meta-analysis for each outcome through a group of programs in the mvmeta and network packages in Stata. Relative odds ratios with 95% confidence intervals were calculated as the result of the analyses. The surface under the cumulative ranking curve (SUCRA) and mean ranks were used to rank these treatments.

RESULTS

Forty-two randomized controlled trials (RCTs) (LTG-placebo: n = 6, LEV-placebo: n = 13, TPM-placebo: n = 9, PER-placebo: n = 6, LCM-placebo: n = 7, LEV-TPM: n = 1) with 10257 participants (LTG = 569, LEV = 1626, TPM = 701, PER = 1734, LCM = 1908, placebo = 3719) were included. Levetiracetam had subequal efficacy in 50 % seizure frequency reduction to TPM [odds ratio (OR) 1.00, 95% confidence interval (CI) 0.73-1.38], and LEV had a higher rate of ≥ 50% seizure frequency reduction than LCM (OR 1.49, 95% CI 1.11-2.01) and PER (OR 1.68, 95% CI 1.24-2.29). Levetiracetam was also related to a higher proportion of seizure freedom participants than TPM (OR 1.87, 95% CI 1.20-2.89), PER (OR 2.23, 95% CI 1.12-4.43), and LCM (OR 2.97, 95% CI 1.46-6.05). In addition, LEV was associated with a lower risk of experiencing at least one treatment-emergent adverse event (TEAE) than PER (OR 0.63, 95% CI 0.46-0.85) and TPM (OR 0.51, 95 % CI 0.36-0.72) and a lower proportion of patients experiencing TEAEs leading to discontinuation than PER (OR 0.51, 95% CI 0.27-0.97) and TPM (OR 0.50, 95 % CI 0.27-0.93).

CONCLUSIONS

Third-generation drugs (PER and LCM) had no advantages in terms of efficacy and safety for adjunctive treatment of refractory epilepsy compared with several second-generation drugs (LEV and LTG). Levetiracetam was the priority choice for adjunctive treatment of refractory epilepsy. Perampanel and LCM had no advantages in terms of efficacy and safety among the five drugs.

REGISTRATION

PROSPERO registration number, CRD42022344153; last edited on December 23, 2022.

Insights into the Cellular Interactions and Molecular Mechanisms of Ketogenic Diet for Comprehensive Management of Epilepsy

A high-fat diet with appropriate protein and low carbohydrate content, widely known as the ketogenic diet (KD), is considered as an effective non-pharmacotherapeutic treatment option for certain types of epilepsies. Several preclinical and clinical studies have been carried out to elucidate its mechanism of antiepileptic action. Ketone bodies produced after KD's breakdown interact with cellular excito-inhibitory processes and inhibit abnormal neuronal firing. The generated ketone bodies decrease glutamate release by inhibiting the vesicular glutamate transporter 1 and alter the transmembrane potential by hyperpolarization. Apart from their effect on the well-known pathogenic mechanisms of epilepsy, some recent studies have shown the interaction of KD metabolites with novel neuronal targets, particularly adenosine receptors, adenosine triphosphate-sensitive potassium channel, mammalian target of rapamycin, histone deacetylase, hydroxycarboxylic acid receptors, and the NLR family pyrin domain containing 3 inflammasomes to suppress seizures. The role of KD in augmenting gut microbiota as a potential mechanism for epileptic seizure suppression has been established. Furthermore, some recent findings also support the beneficial effect of KD against epilepsy- associated comorbidities. Despite several advantages of the KD in epilepsy management, its use is also associated with a wide range of side effects. Hypoglycemia, excessive ketosis, acidosis, renal stones, cardiomyopathies, and other metabolic disturbances are the primary adverse effects observed with the use of KD. However, in some recent studies, modified KD has been tested with lesser side effects and better tolerability. The present review discusses the molecular mechanism of KD and its role in managing epilepsy and its associated comorbidities.

The assessment of cardiac risk in patients taking lamotrigine; a systematic review

OBJECTIVE

The Food and Drug Administration (FDA) warned about lamotrigine's arrhythmogenicity based on in vitro data. This systematic review investigates lamotrigine's effect on cardiac conduction and risk of sudden cardiac death (SCD) in individuals with and without cardiovascular disease.

METHODS

We searched Web of Science and PubMed from inception through August 2021. We included studies measuring electrocardiogram (ECG) changes, laboratory abnormalities, or SCD among patients taking lamotrigine. Studies examining sudden unexpected death in epilepsy were excluded for scope. Two reviewers assessed articles and extracted data. We used the Effective Public Healthcare Panacea Project tool to evaluate confidence in evidence.

RESULTS

Eight randomized controlled trials, 9 nonrandomized observational studies, and 24 case reports were identified, with >3054 total participants, >1606 of whom used lamotrigine. One randomized trial of older patients found an average QRS increase of 3.5 +/- 13.1 ms. Fifteen studies reported no changes in ECG parameters. Case reports documented QRS widening (13), Brugada syndrome (6), QTc prolongation (1) and SCD (2), though many ingested toxic quantities of lamotrigine and/or other medications.

CONCLUSIONS

Evidence is insufficient to support the breadth of the FDA warning concerning lamotrigine's cardiac risk. Lamotrigine at therapeutic doses may be associated with modest, non-dangerous QRS widening.

Cardiac sodium channel inhibition by lamotrigine: in vitro characterization and clinical implications

Lamotrigine, approved for use as an antiseizure medication as well as the treatment of bipolar disorder, inhibits sodium channels in the brain to reduce repetitive neuronal firing and pathological release of glutamate. The shared homology of sodium channels and lack of selectivity associated with channel blocking agents can cause slowing of cardiac conduction and increased proarrhythmic potential. The Vaughan‐Williams classification system differentiates sodium channel blockers using biophysical properties of binding. As such, Class Ib inhibitors, including mexiletine, do not slow cardiac conduction as measured by the electrocardiogram, at therapeutically relevant exposure. Our goal was to characterize the biophysical properties of Na_V1.5 block and to support the observed clinical safety of lamotrigine. We used HEK‐293 cells stably expressing the hNa_V1.5 channel and voltage clamp electrophysiology to quantify the potency (half‐maximal inhibitory concentration) against peak and late channel current, on‐/off‐rate binding kinetics, voltage‐dependence, and tonic block of the cardiac sodium channel by lamotrigine; and compared to clinically relevant Class Ia (quinidine), Ib (mexiletine), and Ic (flecainide) inhibitors. Lamotrigine blocked peak and late Na_V1.5 current at therapeutically relevant exposure, with rapid kinetics and biophysical properties similar to the class Ib inhibitor mexiletine. However, no clinically meaningful prolongation in QRS or PR interval was observed in healthy subjects in a new analysis of a previously reported thorough QT clinical trial (SCA104648). In conclusion, the weak Na_V1.5 block and rapid kinetics do not translate into clinically relevant conduction slowing at therapeutic exposure and support the clinical safety of lamotrigine in patients suffering from epilepsy and bipolar disorder.

Indirect treatment comparison of cenobamate to other ASMs for the treatment of uncontrolled focal seizures

OBJECTIVE

The efficacy and safety of cenobamate relative to other antiseizure medications (ASMs) has not been evaluated. An indirect treatment comparison (network meta-analysis) was performed to determine if adjunctive cenobamate increases the odds ratio (OR) for ≥50% responder rate or for withdrawals due to treatment-emergent adverse events (TEAEs) leading to ASM discontinuation versus adjunctive therapy with other ASMs.

METHODS

A systematic literature review was conducted to identify randomized, double-blind, placebo-controlled trials (maintenance phase ≥ 12 weeks) assessing adjunctive ASMs in adults with uncontrolled focal seizures. Cenobamate was compared to a group of seven other ASMs, and to subgroups of branded (brivaracetam, eslicarbazepine acetate, lacosamide, and perampanel) and older (lamotrigine, levetiracetam, and topiramate) ASMs at FDA-recommended daily maintenance doses (FDA-RDMD), at all doses, and at maximum and minimum daily doses. Statistical significance was set at p < 0.05.

RESULTS

Twenty-one studies were eligible for analysis. The placebo-adjusted ≥ 50% responder rate for FDA-RDMD of cenobamate was superior (OR 4.200; 95% CI 2.279, 7.742) to FDA-RDMD of all seven assessed (OR 2.202 95% CI 1.915, 2.532; p = 0.044) and branded ASMs (OR 2.148; 95% CI 1.849, 2.494; p = 0.037). There was no significant difference for ≥50% responder rate between FDA-RDMD of cenobamate and FDA-RDMD of older ASMs (OR 2.617; 95% CI 1.767, 3.878; p = 0.202). No significant differences were identified for ≥50% responder rate when comparing all doses and maximum/minimum doses of cenobamate to all seven, branded, and older ASMs. Cenobamate demonstrated comparable TEAE withdrawal rates to all seven ASMs, branded ASMs, and older ASMs across each of the four dose ranges (all p > 0.05).

SIGNIFICANCE

Patients receiving FDA-RDMD of cenobamate were more likely to have ≥50% seizure reduction compared with FDA-RDMD of the seven assessed ASMs and branded ASMs, without an increase in treatment discontinuation due to TEAEs.

Redefining the age-specific therapeutic ranges of lamotrigine for patients with epilepsy: A step towards optimizing treatment and increasing cost-effectiveness

OBJECTIVE

The pharmacokinetics of lamotrigine exhibits age-related characteristics. Nevertheless, current evidence regarding the therapeutic range of lamotrigine has been derived almost exclusively from studies in adult patients, and the applicability of this therapeutic range to the pediatric population remains unclear. The purpose of this study was to establish the appropriate age-specific therapeutic ranges of lamotrigine corresponding to adequate clinical responses for patients with epilepsy.

METHODS

This prospective cohort study of therapeutic drug monitoring included 582 Chinese epilepsy patients receiving lamotrigine monotherapy. Patients were divided into three age-related subgroups: (1) toddler and school-age group (2-12 years old, n = 168), (2) adolescent group (12-18 years old, n = 171), and (3) adult group (>18 years old, n = 243). Patients with a reduction in seizure frequency of 50 % or greater than baseline were defined as responders, and the remaining patients were non-responders. The relationship between lamotrigine serum concentrations and clinical response was assessed using multivariate logistic regression analysis. A receiver operating characteristic curve was generated to determine the representative cut-off values of lamotrigine trough levels, to distinguish responders from non-responders. The upper margin of the therapeutic range of lamotrigine was determined by developing concentration-effect curves for the three age-related subgroups.

RESULTS

The median trough levels of lamotrigine were significantly higher in responders than in non-responders from all three age-related groups (P < 0.0001). Results of logistic regression analysis revealed that higher serum concentrations of lamotrigine predicted a higher probability that seizure frequency would be reduced by more than 50 % compared to baseline (adjusted odds ratio: 1.228, 95 % CI: 1.137-1.327; P < 0.0001), and younger children were less likely to be responders (adjusted odds ratio: 1.027, 95 % CI: 1.012-1.043; P = 0.001). Based on a trade-off between sensitivity and specificity, the optimal cut-off values for lamotrigine trough concentrations corresponding to clinical response were 3.29 mg/L, 2.06 mg/L, and 1.61 mg/L in the toddler and school-age group, adolescent group, and adult group, respectively. By reducing interpatient variability, the results of the concentration-effect curves suggested no additional clinical benefit from a continued increase of doses for lamotrigine concentrations exceeding 9.08 mg/L, 8.43 mg/L, and 10.38 mg/L in the toddler and school-age group, adolescent group, and adult group, respectively. In conclusion, the therapeutic ranges of lamotrigine trough concentrations corresponding to adequate clinical response were 3.29-9.08 mg/L in the toddler and school-age group, 2.06-8.43 mg/L in the adolescent group, and 1.61-10.38 mg/L in the adult group.

CONCLUSIONS

The study determined age-specific therapeutic ranges corresponding to optimal clinical efficacy for lamotrigine. Our findings lay the foundation for catalyzing novel opportunities to optimize treatment and reduce therapeutic costs. Based on the age-specific therapeutic ranges identified in this study, individualized and cost-effective algorithms for lamotrigine treatment of epilepsy patients may be developed and validated in larger cohort studies of therapeutic drug monitoring.

Lamotrigine add-on therapy for drug-resistant focal epilepsy

BACKGROUND

This is an updated version of the Cochrane Review previously published in 2016. Epilepsy is a common neurological disorder, affecting 0.5% to 1% of the population. For nearly 30% of these people, their epilepsy is resistant to currently available drugs. Pharmacological treatment remains the first choice to control epilepsy. Lamotrigine is one of the newer antiepileptic drugs. Lamotrigine, in combination with other antiepileptic drugs (add-on), can reduce seizures, but with some adverse effects.

OBJECTIVES

To determine the effects of lamotrigine on (1) seizures, (2) adverse-effect profile, and (3) cognition and quality of life, compared to placebo, when used as an add-on treatment for people with drug-resistant focal epilepsy.

SEARCH METHODS

For the latest update of the review, we searched the following databases on 9 March 2020: Cochrane Register of Studies (CRS Web), MEDLINE (Ovid, 1946 to March 06, 2020). CRS Web includes randomized or quasi-randomized, controlled trials from PubMed, EMBASE, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialized Registers of Cochrane Review Groups including Epilepsy. No language restrictions were imposed.

SELECTION CRITERIA

Randomised placebo-controlled trials of people with drug-resistant focal epilepsy of any age, in which an adequate method of concealment of randomisation was used. The studies were double-, single- or unblinded, placebo-controlled. For cross-over studies, the first treatment period was treated as a parallel trial. Eligible participants were adults or children with drug-resistant focal epilepsy.

DATA COLLECTION AND ANALYSIS

For this update, two review authors independently assessed the trials for inclusion, and extracted data. Outcomes included 50% or greater reduction in seizure frequency, treatment withdrawal (any reason), adverse effects, effects on cognition and quality of life. Primary analyses were by intention-to-treat. Sensitivity best- and worse-case analyses were undertaken to account for missing outcome data. Pooled risk ratios (RRs) with 95% confidence intervals (95% Cls) were estimated for the primary outcomes of seizure frequency and treatment withdrawal. For adverse effects, we calculated pooled RRs and 99% Cls.

MAIN RESULTS

We did not identify any new studies for this update, therefore, the results and conclusions are unchanged. In previous updates of this review, the authors found five parallel add-on studies, eight cross-over studies in adults or children with drug-resistant focal epilepsy, and one parallel add-on study with a responder-enriched design in infants. In total, these 14 studies included 1806 eligible participants (38 infants, 199 children, 1569 adults). Baseline phases ranged from four to 12 weeks; treatment phases from eight to 36 weeks. Overall, 11 studies (1243 participants) were rated as having low risk of bias, and three (697 participants) had unclear risk of bias due to lack of reported information around study design. Effective blinding of studies was reported in four studies (563 participants). The overall risk ratio (RR) for 50% or greater reduction in seizure frequency was 1.80 (95% CI 1.45 to 2.23; 12 trials, 1322 participants (adults and children); moderate-certainty evidence) indicating that lamotrigine was significantly more effective than placebo in reducing seizure frequency. The overall RR for treatment withdrawal (for any reason) was 1.11 (95% CI 0.91 to 1.37; 14 trials; 1806 participants; moderate-certainty evidence). The adverse events significantly associated with lamotrigine were: ataxia, dizziness, diplopia (double vision), and nausea. The RR of these adverse effects were as follows: ataxia 3.34 (99% Cl 2.01 to 5.55; 12 trials; 1525 participants; high-certainty evidence); dizziness 2.00 (99% Cl 1.52 to 2.64;13 trials; 1768 participants; moderate-certainty evidence); diplopia 3.79 (99% Cl 2.15 to 6.68; 3 trials, 944 participants; high-certainty evidence); nausea 1.81 (99% Cl 1.22 to 2.68; 12 studies,1486 participants; moderate-certainty evidence). The limited data available precluded any conclusions about effects on cognition and quality of life. No important heterogeneity between studies was found for any of the outcomes. Overall, we assessed the evidence as high to moderate certainty, due to incomplete data for some outcomes.

AUTHORS' CONCLUSIONS

Lamotrigine as an add-on treatment for drug-resistant focal seizures appears to be effective in reducing seizure frequency, and seems to be fairly well-tolerated. However, the trials were of relatively short duration and provided no evidence for the long term. Further trials are needed to assess the long-term effects of lamotrigine, and to compare lamotrigine with other add-on drugs.

Perspective: Therapeutic Potential of Flavonoids as Alternative Medicines in Epilepsy

Epilepsy is a chronic neurological disorder that affects many people worldwide. Temporal lobe epilepsy is the most common and most studied type of epilepsy, but the pathological mechanisms underlying this condition are poorly understood. More than 20 antiepileptic drugs (AEDs) have been developed and used for the treatment of epilepsy; however, 30% of patients still experience uncontrolled epilepsy and associated comorbidities, which impair their quality of life. In addition, various side effects have been reported for AEDs, such as drowsiness, unsteadiness, dizziness, blurred or double vision, tremor (shakiness), greater risk of infections, bruising, and bleeding. Thus, critical medical needs remain unmet for patients with uncontrolled epilepsy. Flavonoids belong to a subclass of polyphenols that are widely present in fruits, vegetables, and certain beverages. Recently, many studies have reported that some flavonoids elicit various beneficial effects in patients with epilepsy without causing the side effects associated with conventional medical therapies. Moreover, flavonoids may have a property of regulating microRNA expression associated with inflammation and cell survival. These findings suggest that flavonoids, which are more effective but impose fewer adverse effects than conventional AEDs, could be used in the treatment of epilepsy.

Comorbidity between epilepsy and cardiac arrhythmias: Implication for treatment

Epilepsy is often comorbid with either neurological or nonneurological diseases. The association between epilepsy and cardiac arrhythmias is not infrequent, mostly in patients with severe forms of epilepsy or critically ill. Remarkably, these medical conditions share many similarities. Vascular and genetic disorders may predispose to both seizures and abnormalities of cardiac electrophysiology. Repeated and uncontrolled seizures may favor potentially life-threatening arrhythmias. Antiepileptic drugs (AEDs) may facilitate the occurrence of cardiac arrhythmias by acting on ionic channels at heart level. Antiarrhythmic drugs (AADs) can have effects on ionic channels expressed in the brain, as suggested by their efficacy in treating patients with rare forms of epilepsy; AADs may also be proconvulsant, mainly during their overdosage. In clinical practice, the AEDs with the lowest risk to influence cardiac electrophysiology are to be preferred in patients presenting with either seizures or arrhythmias. Traditional AEDs should be avoided because of their arrhythmogenic properties and enzyme-inducing effects, which may make ineffective the concomitant treatment with AADs. Some of the newer AEDs can rarely affect cardiac rhythm, and electrocardiogram (ECG) monitoring should be warranted.

Efficacy of antiepileptic drugs in the adjunctive treatment of refractory partial-onset seizures: Meta-analysis of pivotal trials

OBJECTIVE

In the absence of randomized clinical trials (RCTs) assessing the relative efficacy of antiepileptic drugs (AEDs), meta-analyses are useful resources for informing treatment choices. This meta-analysis assesses the relative efficacy and tolerability of AEDs for adjunctive treatment of refractory partial onset seizures (POS).

METHODS

A systematic literature review was conducted to identify pivotal AED trials serving as the basis for US Food and Drug Administration (FDA) approval.

INCLUSION CRITERIA

1) double-blind, placebo-controlled, parallel-group design, with 8- to 14-week maintenance period; 2) enrolled patients ≥16years with refractory POS, including complex partial seizures; 3) study was conducted between 1993 and 2013; and; 4) patients received FDA-approved dosage. Outcomes analyzed: 1) 50% responder rate (≥50% reduction from baseline in seizure frequency); 2) seizure freedom (proportion of seizure-free patients); and 3) discontinuation due to adverse events (AEs). DerSimonian and Laird random-effects model was used to derive odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

A total of 29 publications for 11 AEDs (eslicarbazepine, ezogabine, gabapentin, lacosamide, levetiracetam, perampanel, pregabalin, tiagabine, topiramate, vigabatrin, and zonisamide) were included in the meta-analysis. Tiagabine 56mg/day (OR 8.82, 95% CI: 2.77-28.11), pregabalin 600mg/day (OR 8.08, 95% CI: 5.45-11.98), and vigabatrin 3000mg/day (OR 6.23, 95% CI: 1.46-26.20) had the highest OR versus placebo of 50% response. The odds of seizure freedom were ≥7 times greater than placebo for levetiracetam 3000mg/day (OR 11.00, 95% CI: 2.08-58.06), vigabatrin 3000mg/day (OR 7.41, 95% CI: 1.31-41.84), and ezogabine 1200mg/day (OR 7.09, 95% CI: 0.36-58.06). Patients were more likely to discontinue any AED (except low-dose pregabalin) than placebo.

CONCLUSION

In this meta-analysis of >9000 patients, those treated with AEDs were more likely than placebo to achieve seizure response or freedom. Patients receiving pregabalin, tiagabine, and vigabatrin had the highest odds of ≥50% reduction in seizures, and patients receiving ezogabine, levetiracetam, and vigabatrin had the highest odds of seizure freedom.

Comparative effectiveness of add-on therapy with newer-generation antiepileptic drugs in Bulgarian patients with refractory epilepsy

OBJECTIVES

The objective of this study is to perform an open, prospective study on various aspects of comparative effectiveness of newer-generation antiepileptic drugs as add-on therapy in Bulgarian patients with drug-resistant epilepsy.

METHODS

The study was performed with the participation of 1259 patients with epilepsy who attended the Clinic of Neurology at the University Hospital in Plovdiv, Bulgaria for regular visits and completed diaries about seizure frequency, severity, and adverse events.

RESULTS

Oxcarbazepine was used in 82 patients, topiramate in 120 patients, lamotrigine in 73 patients, levetiracetam in 135 patients, pregabalin in 47 patients, tiagabine in 43 patients, gabapentin in 18 patients, lacosamide in 12 patients, and retigabine in 6 patients. During the first 24 months of study, improvement of seizure severity and frequency was most frequent in patients on treatment with pregabalin and levetiracetam and rarest in those on treatment with oxcarbazepine. The retention rate of patients on pregabalin and tiagabine was significantly lower compared to the retention rate of patients on most of the other antiepileptic drugs. The frequency of adverse events was higher in patients on treatment with tiagabine and pregabalin.

CONCLUSION

Despite some similar characteristics of newer-generation antiepileptic drugs' effectiveness, levetiracetam stands out with better dynamic improvement of seizure severity and frequency and satisfactory tolerability; typical for pregabalin is a very good dynamic improvement of seizure severity and frequency mainly in patients with focal seizures, but a lower tolerability, and the main advantage of oxcarbazepine is a good tolerability, efficacy, however, is less satisfactory.

Antiepileptic drug treatment of generalized tonic-clonic seizures: An evaluation of regulatory data and five criteria for drug selection

BACKGROUND

A generalized tonic-clonic seizure (GTCS) is the most severe form of common epileptic seizure and carries the greatest risk of harm. The aim of this review is to provide an evidence-based guide for the selection of antiepileptic drugs (AEDs) for patients with GTCSs. Eight AEDs are approved in Europe and the USA for the treatment of both primarily GTCSs (PGTCSs) and secondarily GTCSs (SGTCSs) and are considered in this paper.

METHODS

Each AED is evaluated using five criteria: (1) efficacy, by seizure type (a: PGTCSs and b: SGTCSs); (2) adverse effects; (3) interactions; (4) adherence and dosing; and (5) mechanism of action (MOA). To ensure the inclusions of robust data, only efficacy data accepted by regulatory authorities were considered, and data related to adverse effects, interactions, adherence, and MOA were all extracted from UK Summaries of Product Characteristics (SPCs).

RESULTS

(1a) There is class 1 evidence of the efficacy of only four AEDs in controlling PGTCSs (lamotrigine, levetiracetam, perampanel, and topiramate). (1b) There is no class 1 evidence of the efficacy of any AED in SGTCSs although some evidence from pooled/subgroup analyses or meta-analyses supports the use of the four AEDs (levetiracetam, perampanel, topiramate, and with less robust data for lamotrigine). (2) AEDs are associated with different, but to some extent overlapping, common adverse effect profiles but have differing idiosyncratic adverse effects. (3) Pharmacokinetic interactions are seen with most, but not all, AEDs and are most common with carbamazepine and phenytoin. (4) Good adherence is important for seizure control and is influenced by frequency of dosing, among other factors. (5) Mechanism of action is also a consideration in rationalising AED selection when switching or combining AEDs.

CONCLUSION

Ultimately, the choice of AED depends on all these factors but particularly on efficacy and adverse effects. Different patients will weigh the various factors differently, and the role of the treating physician is to provide accurate information to allow patients to make informed choices.

Incidence of seizure exacerbation and seizures reported as adverse events during adjunctive treatment with eslicarbazepine acetate: A pooled analysis of three Phase III controlled trials

Objective

To investigate whether adjunctive eslicarbazepine acetate (ESL) could lead to exacerbation of seizures in some patients.

Methods

Post-hoc analysis of data pooled from three Phase III trials of adjunctive ESL (studies 301, 302, and 304) for refractory partial-onset seizures (POS). Following an 8-week baseline period, patients were randomized to receive placebo or ESL 400, 800, or 1,200 mg once daily (2-week titration, 12-week maintenance, 2-4 week tapering-off periods). Patient seizure diary data and seizure treatment-emergent adverse event (TEAE) reports were pooled for analysis.

Results

The modified intent-to-treat and safety populations comprised 1,410 patients and 1,447 patients, respectively. Titration period: Compared with placebo (32/21%), significantly smaller proportions of patients taking ESL 800 mg (20/15%) and 1,200 mg (22/12%) had a ≥25/≥50% increase in standardized seizure frequency (SSF) from baseline; there was no significant difference between placebo and ESL 400 mg. Maintenance period: Compared with placebo (20%), significantly smaller proportions of patients taking ESL (400 mg, 12%; 800 mg, 12%; 1,200 mg, 14%) had an increase in SSF ≥25%. When evaluating ≥50% increases in SSF, only ESL 800 mg (7%) was significantly different from placebo (12%). Some patients had no secondarily generalized tonic-clonic (sGTC) seizures during baseline but had ≥1 sGTC seizure during maintenance treatment (placebo, 11%; ESL 400 mg, 5%; 800 mg, 10%; 1,200 mg, 5%). Fewer patients had a ≥25% increase in sGTC seizure frequency with ESL (400 mg, 11%; 800 mg, 9%; 1,200 mg, 14%) versus placebo (19%). The incidence of seizures reported as TEAEs was low in all treatment groups; incidences were generally lower with ESL versus placebo. Tapering-off period: Similar proportions of patients taking ESL and placebo had a ≥25/≥50% increase in SSF. Seizure TEAE incidence was numerically higher with ESL versus placebo.

Significance

Treatment with adjunctive ESL does not appear to aggravate POS or sGTC seizures.

Association between antiepileptic drug dose and long-term response in patients with refractory epilepsy

Seizures in patients with medically refractory epilepsy remain a substantial clinical challenge, not least because of the dearth of evidence-based guidelines as to which antiepileptic drug (AED) regimens are the most effective, and what doses of these drugs to employ. We sought to determine whether there were regions in the dosage range of commonly used AEDs that were associated with superior efficacy in patients with refractory epilepsy. We retrospectively analyzed treatment records from 164 institutionalized, developmentally disabled patients with refractory epilepsy, averaging 17years of followup per patient. We determined the change in seizure frequency in within-patient comparisons during treatment with the most commonly used combinations of 12 AEDs, and then analyzed the response to treatment by quartile of the dose range for monotherapy with carbamazepine (CBZ), lamotrigine (LTG), valproate (VPA), or phenytoin (PHT), and the combination LTG/VPA. We found that of the 26 most frequently used AED regimens, only LTG/VPA yielded superior efficacy, similar to an earlier study. For the monotherapies, patients who were treated in the lowest quartile of the dose range had significantly better long-term reduction in seizure frequency compared to those treated in the 2nd and 3rd quartiles of the dose range. Patients with paired exposures to CBZ in both the lowest quartile and a higher quartile of dose range experienced an increase in seizure frequency at higher doses, while patients treated with LTG/VPA showed improved response with escalation of LTG dosage. We conclude that in this population of patients with refractory epilepsy, LTG/VPA was the most effective AED combination. The best response to AEDs used in monotherapy was observed at low dosage. This suggests that routine exposure to maximally tolerated AED doses may not be necessary to identify those patients with drug-resistant seizures who will have a beneficial response to therapy. Rather, responders to a given AED regimen may be identified with exposure to low AED doses, with careful evaluation of the response to subsequent titration to identify non-responders or those with exacerbation of seizure frequency at higher doses.

Lamotrigine Reduces Inflammatory Response and Ameliorates Executive Function Deterioration in an Alzheimer's-Like Mouse Model

Alzheimer's disease (AD) has been described in the literature, to be associated with impairment of executive function which develops early in the course of disease, and an effective treatment for this clinical feature remains elusive. Preclinical studies have implied that lamotrigine, an antiepileptic agent, could be a potential treatment for executive dysfunction in AD patients. Although there have been promising results in previous studies with lamotrigine, executive function has never been measured using animal models. The aim of the present study was to evaluate the effects of lamotrigine on executive function and determine whether lamotrigine can attenuate inflammatory response in an AD mouse model. Nontransgenic and transgenic mice were treated with lamotrigine (0 or 30 mg/kg/day) in a standard laboratory chow diet starting at 3 months of age. After 6 months of continuous lamotrigine administration, there was a marked improvement in executive function and a significant attenuation in the expression of proinflammatory cytokines. These results suggest that lamotrigine could ameliorate executive dysfunction and brain inflammatory response in the mouse model of AD and early lamotrigine intervention may be a promising therapeutic strategy for AD.

Assessing the Cost-Effectiveness of New Pharmaceuticals in Epilepsy in Adults: The Results of a Probabilistic Decision Model

Epilepsy currently affects more than 400,000 people in the United Kingdom and 2.3 million in the United States. Drug therapy is the mainstay of treatment for patients with epilepsy, but therapies vary widely in their mechanism of action and acquisition cost. This article describes a decision model developed for the National Institute for Clinical Excellence in the United Kingdom. It compares the long-term cost-effectiveness of drugs licensed in adults for use in 3 situations: monotherapy for newly diagnosed patients, monotherapy for refractory patients, and combination therapy for refractory patients. The analysis separately considers the treatment of partial and generalized seizures. The full range of pharmaceutical therapies feasibly used in the UK health system was included in the analysis. The analysis showed that, on the basis of existing evidence, for newly diagnosed patients with partial seizures, carbamazepine and valproate are likely to be the most cost-effective mono-therapies. Carbamazepine is likely to be the most cost-effective 2nd-line monotherapy for refractory patients, and oxcarbazepine would probably be the most cost-effective adjunctive therapy for refractory patients if the willingness to pay for additional health benefits is greater than £18,000 per quality-adjusted life year (QALY). For patients with generalized seizures, valproate is most likely to be cost-effective for newly diagnosed patients. For refractory patients, adjunctive topiramate is more cost-effective than monotherapy alone if the willingness to pay for additional health benefits is greater than £35,000 per QALY. There is, however, considerable uncertainty regarding these results. Some of the methodological features of the study will be of value in designing cost-effectiveness analyses of other therapies for chronic conditions. These include the methods used to deal with the absence of head-to-head trial data and the need to reflect time dependency in Markov transition probabilities.

Reversible Valproate Induced Pisa Syndrome and Parkinsonism in a Neuro-Oncology Patient with Depression and Epilepsy

Neurological and psychiatric conditions frequently overlap in neuro-oncology. This overlapping negatively affects patients' quality of life and decreases the ability of providers to manage specific symptoms by therapy modulation, especially when psychopharmacotherapy needs to be prescribed. We describe here a patient with recurrent brain tumor, symptomatic epilepsy and depression who developed Pisa syndrome and parkinsonism after several months of valproic acid use. An accurate recognition of symptoms and treatment side effect allowed an appropriate clinical approach so as to rapidly improve both movement disorder and depression without increasing the risk of developing seizure. This has improved the autonomy and quality of life in a patient with poor prognosis.

Lamotrigine add-on for drug-resistant partial epilepsy

BACKGROUND

This is an updated version of the Cochrane review published in The Cochrane Library 2010, Issue 1.Epilepsy is a common neurological disorder, affecting almost 0.5% to 1% of the population. For nearly 30% of these people, their epilepsy is refractory to currently available drugs. Pharmacological treatment remains the first choice to control epilepsy. Lamotrigine is one of the newer antiepileptic drugs and is the topic of this review. Lamotrigine in combination with other antiepileptic drugs (add-on) can reduce seizures, but with some adverse effects. The aim of this systematic review was to overview the current evidence for the efficacy and tolerability of lamotrigine when used as an adjunctive treatment for people with refractory partial epilepsy.

OBJECTIVES

To determine the effects of lamotrigine on (1) seizures, (2) adverse effect profile, and (3) cognition and quality of life, compared to placebo controls, when used as an add-on treatment for people with refractory partial epilepsy.

SEARCH METHODS

For the previous version of the review, the authors searched the Cochrane Epilepsy Group Specialized Register (January 2010), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2010, Issue 1), MEDLINE (1950 to January 2010), and reference lists of articles.For this update, we searched the Cochrane Epilepsy Group Specialized Register (28 May 2015), CENTRAL (The Cochrane Library 2015, Issue 4), MEDLINE (Ovid, 1946 to May 2015), and reference lists of articles. We also contacted the manufacturers of lamotrigine (GlaxoSmithKline). No language restrictions were imposed.

SELECTION CRITERIA

Randomised placebo-controlled trials of people with drug-resistant partial epilepsy of any age, in which an adequate method of concealment of randomisation was used. The studies were double-, single- or unblinded. For cross-over studies, the first treatment period was treated as a parallel trial. Eligible participants were adults or children with drug-resistant partial epilepsy.

DATA COLLECTION AND ANALYSIS

For this update, two review authors independently assessed the trials for inclusion, and extracted data. Outcomes included 50% or greater reduction in seizure frequency, treatment withdrawal (any reason), adverse effects, effects on cognition and quality of life. Primary analyses were by intention-to-treat. Sensitivity best and worse case analyses were undertaken to account for missing outcome data. Pooled Risk Ratios (RR) with 95% confidence intervals (95% Cl) were estimated for the primary outcomes of seizure frequency and treatment withdrawal. For adverse effects, pooled RRs and 99% Cls were calculated.

MAIN RESULTS

We did not identify any new studies for this update, therefore, the results are unchanged.For the previous version of the review, the authors found five parallel add-on studies and eight cross-over studies in adults or children with refractory focal epilepsy, and one parallel add-on study with a responder-enriched design in infants. In total, these 14 studies included 1958 participants (38 infants, 199 children, and 1721 adults). Baseline phases ranged from 4 to 12 weeks; treatment phases from 8 to 36 weeks. Overall, eleven studies (n = 1243 participants) were rated as having a low risk of bias, and three (n = 715 participants) had un unclear risk of bias due to lack of reported information around study design. Effective blinding of studies was reported in three studies (n = 504 participants). The overall risk ratio (RR) for 50% or greater reduction in seizure frequency was 1.80 (95% CI 1.45 to 2.23; 12 RCTs) for twelve studies (n = 1322 participants, adults and children) indicating that lamotrigine was significantly more effective than placebo in reducing seizure frequency. The overall RR for treatment withdrawal (for any reason) was 1.11 (95% CI 0.90 to 1.36; 14 RCTs) for fourteen studies (n = 1958 participants). The adverse events significantly associated with lamotrigine were: ataxia, dizziness, diplopia, and nausea. The RR of these adverse effects were as follows: ataxia 3.34 (99% Cl 2.01 to 5.55; 12 RCTs; n = 1524); dizziness 2.00 (99% Cl 1.51 to 2.64;13 RCTs; n = 1767); diplopia 3.79 (99% Cl 2.15 to 6.68; 3 RCTs; n = 943); nausea 1.81 (99% Cl 1.22 to 2.68; 12 RCTs; n = 1486). The limited data available precluded any conclusions about effects on cognition and quality of life. No important heterogeneity between studies was found for any of the outcomes. Overall, we assessed the evidence as high to moderate quality, due to incomplete data for some outcomes.

AUTHORS' CONCLUSIONS

Lamotrigine as an add-on treatment for partial seizures appears to be effective in reducing seizure frequency, and seems to be fairly well tolerated. However, the trials were of relatively short duration and provided no evidence for the long-term. Further trials are needed to assess the long-term effects of lamotrigine, and to compare it with other add-on drugs.Since we did not find any new studies, our conclusions remain unchanged.

A long-term noninterventional safety study of adjunctive lacosamide therapy in patients with epilepsy and uncontrolled partial-onset seizures

This noninterventional, observational, postauthorization safety study (SP0942, NCT00771927) evaluated the incidence of predefined cardiovascular- (CV) and psychiatric-related treatment-emergent adverse events (TEAEs), in patients with epilepsy and uncontrolled partial-onset seizures, when initiating adjunctive therapy with lacosamide or another approved antiepileptic drug (AED) according to standard medical practice. Active recording of predefined TEAEs of interest took place at three-monthly recommended visits for up to 12months. Of 1004 patients who received at least one dose of adjunctive AEDs, 511 initially added lacosamide therapy, 493 added another AED, 69 were ≥65years of age, and 72 took concomitant antiarrhythmic drugs. Patients in the lacosamide cohort had a higher median frequency of partial-onset seizures (6.0 versus 3.5 per 28days) despite taking more concomitant AEDs (84.9% versus 66.9% took ≥2) at baseline. Patients who added lacosamide took a modal dose of 200mg/day over the treatment period (n=501), and 50.1% (256/511) completed 12months of treatment. Fifty-one point nine percent (256/493) of patients who added another AED completed the study, with the most commonly added AED being levetiracetam (28.4%). Four patients (0.8%) in each cohort, all <65years of age, reported predefined CV-related TEAEs. None were considered serious or led to discontinuation. One event each of sinus bradycardia (lacosamide), atrioventricular block first degree (lacosamide), and syncope (other AED) were judged to be treatment-related. Another patient in the other AED cohort reported bradycardia while taking concomitant antiarrhythmic drugs. Predefined psychiatric-related TEAEs were reported by 21 patients (4.1%) in the lacosamide cohort and 27 patients (5.5%) in the other AED cohort. Depression was the most common to be treatment-related (7/11 and 12/18 of patients reporting treatment-related psychiatric TEAEs, respectively). Serious psychiatric-related TEAEs were reported by four patients who added lacosamide (two cases of depression, two of suicide attempt) and one who added another AED (depression). Seven deaths occurred, all of which were considered unrelated/unlikely related to study medication. This thorough evaluation revealed a low incidence of predefined CV- and psychiatric-related TEAEs in patients taking adjunctive AED therapy according to standard medical practice. No specific safety concerns related to adjunctive lacosamide therapy were noted.

Lamotrigine as monotherapy in clinical practice: efficacy of various dosages in epilepsy

OBJECTIVES/AIMS

The study was designed to evaluate the optimal dosage of lamotrigine, as monotherapy, in the treatment of adults suffering from complex partial seizures with or without secondary generalization in everyday clinical practice.

MATERIALS AND METHODS

The ones used in this study was the collection of the data of all adult patients treated with lamotrigine, retrospectively. The dosage and efficacy of treatment were evaluated along with side effects and retention rate.

RESULTS

They showed that, out of 188 patients, 77% continued lamotrigine treatment; the mean effective dose was 250 mg or higher of lamotrigine, and the results more pronounced in older patients (age above 30 years) and those with a longer disease duration (5 years and more).

CONCLUSION

It may be appropriate to reach a daily lamotrigine dose above 250 mg in adult patients suffering from epilepsy for more than 5 years using lamotrigine as monotherapy.

Lacosamide cardiac safety: clinical trials in patients with partial-onset seizures

OBJECTIVE

To evaluate the cardiac safety of adjunctive lacosamide in a large pool of adults with partial-onset seizures (POS).

METHODS

Post-randomization changes from baseline for electrocardiographic (ECG) measurements, diagnostic findings, and relevant adverse events (AEs) were compared for pooled data from three randomized, placebo-controlled trials of adjunctive lacosamide for the treatment of POS.

RESULTS

Lacosamide did not prolong the QTc interval or affect heart rate as determined by an analysis of data from patients randomized to lacosamide 200, 400, or 600 mg/day (n = 944) compared with placebo (n = 364). After 12-week maintenance treatment, mean changes from baseline for QRS duration were similar between the placebo and lacosamide 200 and 400 mg/day groups (0.0, -0.2, and 0.4 ms), but slightly increased for lacosamide 600 mg/day (2.3 ms). A small, dose-related mean increase in PR interval was observed (-0.3, 1.4, 4.4, and 6.6 ms for the placebo and lacosamide 200, 400, and 600 mg/day groups, respectively). First-degree atrioventricular (AV) block was reported as a non-serious AE in 0.0%, 0.7%, 0.2%, and 0.5% of patients in the same respective groups. Second- or higher degree AV block was not observed. There was no evidence of a PR-interval-related pharmacodynamic interaction of lacosamide with either carbamazepine or lamotrigine.

CONCLUSIONS

Evaluation of the pooled cardiac safety data from patients with POS showed that adjunctive lacosamide at the maximum recommended dose (400 mg/day) was not clearly associated with any cardiac effect other than a small, dose-related increase in PR interval that had no evident symptomatic consequence.

GWAS identifies two susceptibility loci for lamotrigine-induced skin rash in patients with epilepsy

PURPOSE

Lamotrigine (LTG)-induced maculopapular eruption (MPE) often causes treatment discontinuation and rising burdens on current healthcare systems. We conducted a genome-wide association study to identify novel susceptibility loci associated with LTG-induced MPE in patients with epilepsy.

MATERIALS AND METHODS

We enrolled patients with LTG-induced MPE (n=34) and utilized the Korea Association Resource project cohort as a control group (n=1214). We explored associations between LTG-induced MPE and single nucleotide polymorphisms (SNPs) through imputation and replicated these associations in samples from 59 LTG-induced MPE cases and 98 LTG tolerant-controls.

RESULTS

We found two novel SNPs associated with LTG-induced MPE: rs12668095 near CRAMP1L/TMEM204/IFT140/HN1L (P=4.89×10(-7)) and rs79007183 near TNS3 (P=3.15×10(-10)), both of which were replicated in an independent cohort.

CONCLUSION

These two validated SNPs may be good candidate markers for predicting LTG-induced MPE in epilepsy patients, although further experimental validation is needed.

Antiepileptic drugs--a review

Epilepsy is a common neurological condition that affects approximately 1% of the general population. In addition, about 10% of the population experiences a seizure sometime during life. The treatment options for epilepsy have come a long way from the bromides to the current era in which we now have multiple treatment modalities, including medications, implantable devices, and surgery. Antiepileptic drugs (AEDs) are the mainstay for treatment of epilepsy with about 70% of children achieving good control with medications alone. The past decade has witnessed the emergence of multiple AEDs-with more than 24 AEDs to choose from presently. The newer drugs provide us with novel mechanisms of action and improved safety profile. This expanded choice of AEDs has made it possible to offer tailored-treatment plans based on unique patient profiles. However, such an ever-increasing choice of medications also poses a challenge for the treating physician as far as choosing the initial drug is concerned-especially because there is limited data comparing the efficacy of one drug to the other. An additional humbling fact remains that, despite an increase in the choice of medications, we are still only able to treat the symptoms of seizures without making any significant progress in reversing or stopping the underlying mechanism of epileptogenesis or in offering neuroprotection from epileptogenesis. Therefore, it is not surprising that, despite the wide array of AED choices, the prevalence of drug-resistant epilepsy has not improved. This article aims at giving a short overview of currently available AEDs.

Drug-induced cerebellar ataxia: a systematic review

BACKGROUND AND OBJECTIVES

Cerebellar ataxia can be induced by a large number of drugs. We here conducted a systemic review of the drugs that can lead to cerebellar ataxia as an adverse drug reaction (ADR).

METHODS

We performed a systematic literature search in Pubmed (1966 to January 2014) and EMBASE (1988 to January 2014) to identify all of the drugs that can have ataxia as an ADR and to assess the frequency of drug-induced ataxia for individual drugs. Furthermore, we collected reports of drug-induced ataxia over the past 20 years in the Netherlands by querying a national register of ADRs.

RESULTS

Drug-induced ataxia was reported in association with 93 individual drugs (57 from the literature, 36 from the Dutch registry). The most common groups were antiepileptic drugs, benzodiazepines, and antineoplastics. For some, the number needed to harm was below 10. Ataxia was commonly reversible, but persistent symptoms were described with lithium and certain antineoplastics.

CONCLUSIONS

It is important to be aware of the possibility that ataxia might be drug-induced, and for some drugs the relative frequency of this particular ADR is high. In most patients, symptoms occur within days or weeks after the introduction of a new drug or an increase in dose. In general, ataxia tends to disappear after discontinuation of the drug, but chronic ataxia has been described for some drugs.

Developing antiepileptic drugs in children: balancing protection and access

This chapter addresses the issue of the balance between protection of children submitted to research and children's access to new treatments, focusing on the field of antiepileptic drugs. Due to the lack of interest pharmaceutical companies have for such an unrewarding market, ethical and legal problems, difficulties recruiting patients, and in Europe insufficient public resources, many infants and children with epilepsy are still exposed to off-label drugs. The incentives and regulations specifically directed toward research in children in the United States and EU provided the first step to change this condition. The challenge is to perform trials determined by the needs of children and to obtain benefits in the same order of magnitude as for adults but with reduced risks. In order to optimize the development of new AEDs in pediatrics, the new European guidelines (2010) recommend the identification of adult clinical trial results that can be extrapolated to the pediatric population (i.e., those in partial epilepsies) and the use of innovative strategies that help limit the number of pediatric patients enrolled in trials (i.e., those with epileptic encephalopathies). A key step will be to develop international networks of pediatric epilepsy centers with the shared purpose of optimizing development and execution of clinical trials.

Cardiac phenomena during kainic-acid induced epilepsy and lamotrigine antiepileptic therapy

RATIONALE

Pathologic ECG events are known to accompany seizures and to persist in several chronic epilepsy syndromes. The contribution of antiepileptic drugs (AEDs) to these events and the implications in the etiology of sudden-unexpected death in epilepsy (SUDEP) continue to be a matter of debate. We therefore investigated cardiac parameters during kainic-acid (KA) induced experimental epilepsy and antiepileptic treatment with lamotrigine (LTG).

METHODS

Epilepsy was induced in seven C57Bl/6 mice by injections of KA (20 mg/kg) on days 1 and 5, which produced severe acute seizures and spontaneous seizures 10 days later. Treatment with LTG (30 mg/kg) was initiated on day 11 and repeated on day 12. Continuous ECGs and ECoGs were collected telemetrically from freely moving mice.

RESULTS

Mice displayed pre-ictal but not ictal tachycardia. The squared coefficient of variation (SCV) of R-R intervals was significantly elevated 30s before and during seizures compared to control conditions. LTG produced a significant reversible increase in SCV and LF/HF ratio during slow-wave sleep (SWS), potentially indicative of sympatho-vagal imbalance during this state of vigilance, in which epileptic patients are known to be particularly vulnerable to SUDEP.

SIGNIFICANCE

The KA model used in this study permits the investigation of cardiac phenomena during epilepsy, as it features many effects found in human epileptic patients. Increased LF/HF, a known risk factor for cardiac disease, which is often found in epileptic patients, was observed as a side-effect of LTG treatment during SWS, suggesting that LTG may promote imbalance of the autonomous nervous system in epileptic mice.

Lamotrigine and its applications in the treatment of epilepsy and other neurological and psychiatric disorders

Lamotrigine is a broad-spectrum antiepileptic drug, initially approved in 1994 for the adjunctive treatment of partial seizures in adults and for the generalized seizures of Lennox-Gastaut syndrome in pediatric (>2 years old) and adult populations. Its role in the treatment of bipolar disorder type I has also been well established. In addition, lamotrigine has been successfully used for the management of other neurological conditions such as migraines and neuropathic pain, and preliminary data show promising results. It has favorable pharmacokinetic properties and is generally well tolerated. The small risk of serious skin rash can be minimized with slow titration of the drug and dose adjustment with concomitant medications. Lamotrigine has demonstrated particular benefit in the treatment of women and elderly patients with epilepsy.

Comparative efficacy and tolerability of anti-epileptic drugs for refractory focal epilepsy: systematic review and network meta-analysis reveals the need for long term comparator trials

AIMS

To evaluate the comparative efficacy (50% reduction in seizure frequency) and tolerability (premature withdrawal due to adverse events) of anti-epileptic drugs (AEDs) for refractory epilepsy.

METHODS

We searched Cochrane Central Register of Controlled Trials (Cochrane Library 2009, issue 2) including Epilepsy Group's specialized register, MEDLINE (1950 to March 2009), EMBASE (1980 to March 2009), and Current Contents Connect (1998 to March 2009) to conduct a systematic review of published studies, developed a treatment network and undertook a network meta-analysis.

RESULTS

Forty-three eligible trials with 6346 patients and 12 interventions, including placebo, contributed to the analysis. Only three direct drug comparator trials were identified, the remaining 40 trials being placebo-controlled. Conventional random-effects meta-analysis indicated all drugs were superior in efficacy to placebo (overall odds ratio (OR] 3.78, 95% CI 3.14, 4.55) but did not permit firm distinction between drugs on the basis of the efficacy or tolerability. A Bayesian network meta-analysis prioritized oxcarbazepine, topiramate and pregabalin on the basis of short term efficacy. However, sodium valproate, levetiracetam, gabapentin and vigabatrin were prioritized on the basis of short-term efficacy and tolerability, with the caveat that vigabatrin is recognized as being associated with serious visual disturbance with chronic use.

CONCLUSION

Of the wide range of AEDs licensed for the treatment of refractory epilepsy, sodium valproate, levetiracetam and gabapentin demonstrated the best balance of efficacy and tolerability. Until regulators mandate greater use of active comparator trials with longer term follow-up, network meta-analysis provides the only available means to quantify these clinically important parameters.

Lamotrigine serum concentration in children with epilepsy

The correlation between lamotrigine serum concentration, efficacy, and toxicity in children is controversial. The database of the Clinical Pharmacology Laboratory at Assaf Harofeh Medical Center was retrospectively searched to identify lamotrigine serum concentrations in children aged 2-19 years with refractory epilepsy who received lamotrigine as monotherapy or polytherapy from 2007-2010. Data collected included age at epilepsy onset, additional antiepileptic drugs, lamotrigine dose, monthly seizure frequency before and after lamotrigine treatment, and side effects. Sixty blood samples were collected from 42 children aged 10.1 ± 4.9 years (range, 2-20 years). Seizure types included complex partial (n = 28), simple partial (n = 7), absence (n = 2), and generalized tonic-clonic (n = 23). Decreased seizure frequency was observed in 38 (63.3%) patients. No correlation with lamotrigine serum concentration was evident, but seizure frequency was significantly influenced by age and lamotrigine dose. Side effects were reported in 21 (35%) patients. Only diplopia was significantly correlated with lamotrigine serum concentration. Lamotrigine was more effective at lower doses and in older children. Lamotrigine serum concentration correlated significantly with diplopia, but not with other side effects or with clinical efficacy. Overall, lamotrigine is effective and safe in children with refractory epilepsy.

Lamotrigine in epilepsy, pregnancy and psychiatry--a drug for all seasons?

Lamotrigine has been demonstrated to be effective as both an antiepileptic drug and a mood stabiliser. For epilepsy it is less efficacious than valproate in primary generalised epilepsy, but it is comparable to some traditional drugs in partial epilepsy. In psychiatry it has significant advantages over other mood stabilisers for the treatment and prevention of depressive phases of bipolar illness, but not for the treatment of mania. It has a more benign adverse effect profile than older antiepileptic agents and is not a proven teratogen. Risk of adverse reactions is reduced by commencing treatment at a markedly reduced dose that is gradually increased.

Effect of second-generation antiepileptic drugs on diplopia: a meta-analysis of placebo-controlled studies

Different antiepileptic drugs (AEDs) may cause similar adverse effects, one of which is diplopia. However, the AEDs causing diplopia and the dose-response effect of each drug remains uncertain. In this study, we compared several second-generation AEDs to find out whether they would contribute to the risk of diplopia and their effect-causing dose. A meta-analysis was performed on 19 studies in agreement with our inclusion criteria. The results showed that eight commonly used second-generation AEDs (gabapentin, levetiracetam, oxcarbazepine, lamotrigine, pregabalin, topiramate, vigabatrin and zonisamide) could cause diplopia. The reported odds ratios (ORs) ranged from 1.406 to 7.996. Ranking risks from the highest to the lowest ORs of the eight AEDs of any dose resulted in the following order: use of oxcarbazepine (7.996), levetiracetam (7.472), lamotrigine (5.258), vigabatrin (3.562), pregabalin (3.048), topiramate (2.660), gabapentin (1.966), zonisamide (1.406). Taking into account the ORs above, we can conclude that second-generation AEDs of any dose may cause diplopia. However, the levetiracetam-caused diplopia needs to be further studied according to the data (OR, 7.472; 95% confidence interval, 0.375-148.772). These findings ask for better concerns about patients' quality of life when giving antiepileptic treatments.

Atrioventricular block following lacosamide intoxication

Lacosamide (LCM) is a novel anticonvulsant that modulates voltage-dependent sodium channels. Although it is known to cause a slight, dose-dependent prolongation of the PR interval on the ECG, third-degree atrioventricular (AV) block has been described as an adverse event in only a few patients participating in diabetic neuropathic pain studies and in no patient with epilepsy. We describe an 89-year old patient with decreased renal function and taking two other negative dromotropic agents who accidentally received two intravenous boli of 400 mg LCM within 6 hours. She had a normal PQ interval before and after the first dose of LCM and developed a reversible complete AV block approximately 30 minutes after the second bolus. We conclude that particular caution must be exercised when using very high doses of LCM in patients with significant cardial and renal risk factors.

Pharmacotherapy of epilepsy: newly approved and developmental agents

This article discusses seven newly available antiepileptic drugs (AEDs) and agents in phase III development. Lacosamide, licensed as an adjunctive treatment for partial-onset seizures, primarily acts by enhancing sodium channel slow inactivation. At daily doses of 200-600 mg, the drug significantly reduced partial-onset seizures in adults with refractory epilepsy. The most common adverse effects are CNS related. Rufinamide, available as adjunctive treatment for seizures associated with Lennox-Gastaut syndrome, has an unclear mechanism of action, although it does block voltage-dependent sodium channels. Coadministration of valproic acid significantly increases rufinamide circulating concentrations. The drug has been shown to have efficacy for partial-onset, primary generalized tonic-clonic, tonic-atonic, absence and atypical absence seizures. Adverse effects are mainly somnolence, nausea and vomiting. Eslicarbazepine acetate, a carbamazepine analogue, was recently licensed as adjunctive treatment for partial-onset seizures. Eslicarbazepine acetate acts at voltage-gated sodium channels, although the precise mechanism of action is unclear. The drug had efficacy for partial-onset seizures in three randomized, double-blind, placebo-controlled studies, using 400, 800 or 1200 mg/day. Adverse effects include dizziness and somnolence. Retigabine (ezogabine) exerts its anticonvulsant effect through the opening of neuronal voltage-gated potassium channels. Following significant seizure reduction rates at dosages of 600, 900 and 1200 mg/day, license applications have been submitted for its use as adjunctive treatment for patients with partial-onset seizures. Dose-related adverse effects include somnolence, confusion and dizziness. Brivaracetam is the n-propyl analogue of levetiracetam. Mixed results have been obtained in phase III studies in patients with partial-onset seizures, and further trials in children, patients with photosensitive epilepsy and patients with partial-onset seizures are ongoing. Dizziness, headache and somnolence are the most common adverse effects reported. Perampanel was designed as an AMPA-type glutamate receptor antagonist. Following encouraging results from phase II studies in patients with refractory partial-onset seizures, recruitment for phase III trials is almost complete. Ganaxolone is a neurosteroid with potent antiepileptic activity that modulates GABA(A) receptors in the CNS. Ganaxolone has shown promise in a variety of seizure types. Dizziness and somnolence have been reported in some patients. The availability of new AEDs has widened the choices for clinicians treating patients with epilepsy. However, given the minimal improvement in prognosis and disappointing efficacy outcomes in double-blind, placebo-controlled, dose-ranging regulatory trials, it seems unlikely that these novel agents will have a major impact on outcomes for people with epilepsy.

Factors determining response to antiepileptic drugs in randomized controlled trials. A systematic review and meta-analysis

PURPOSE

Because of the lack of head-to-head adjunctive-therapy trials of antiepileptic drugs (AEDs) in refractory partial epilepsy, meta-analyses of placebo-controlled randomized controlled trials (RCTs) represent a potentially important source of evidence to guide treatment decisions. However, such indirect comparisons raise various methodologic issues that may hamper their relevance.

METHODS

All RCTs in adult refractory partial epilepsy were analyzed to assess whether efficacy outcomes are influenced by: characteristics of patients and trials ; use of last observation carried forward (LOCF) analysis; evaluation period (entire period versus maintenance period); and year of publication. A meta-analysis of these AEDs was then performed taking these factors into consideration.

KEY FINDINGS

Sixty-three RCTs evaluating 20 AEDs were included. The following variables influenced efficacy estimates: (1) responder rates correlated positively with duration of the entire treatment period (p = 0.038); (2) response to placebo was significantly greater in the maintenance period than in the entire treatment period (p = 0.005); (3) responder rates increased over the years both for AEDs (p < 0.001) and for placebo (p = 0.001); (4) LOCF analysis overestimated responder rates for AEDs (p < 0.001) and for placebo (p = 0.001) compared with completer-based analysis, and the overestimation correlated positively with withdrawal rates (p < 0.001). A meta-analysis of available data showed large differences in efficacy ranking in relation to dose selection and type of analysis, but these were mostly nonsignificant due to statistical power limitations.

SIGNIFICANCE

Several methodologic issues hamper the relevance of indirect comparisons of AEDs in the adjunctive-therapy of refractory partial epilepsy. Some of these issues could be overcome by improved standardization in the reporting of efficacy outcomes.

Adjunctive lamotrigine XR for primary generalized tonic-clonic seizures in a randomized, placebo-controlled study

Efficacy and tolerability of once-daily adjunctive lamotrigine extended-release (XR) for primary generalized tonic-clonic (PGTC) seizures in epilepsy were evaluated. Patients (n = 153) ≥ 13 years old diagnosed with epilepsy with PGTC seizures were randomized to once-daily adjunctive lamotrigine XR or placebo in a double-blind, parallel-group trial comprising a baseline phase, a 7-week double-blind escalation phase, and a 12-week double-blind maintenance phase. Lamotrigine XR was more effective than placebo with respect to median percentage reduction from baseline in weekly PGTC seizure frequency (primary endpoint-19-week treatment phase: 75.4% vs 32.1%, P<0.0001; escalation phase: 61.9% vs 30.6%, P = 0.0016; maintenance phase: 89.7% vs 33.3%, P<0.0001). Lamotrigine XR was more effective than placebo with respect to the percentage of patients with ≥50% reduction in PGTC seizure frequency. Significant separation from placebo for ≥50% reduction in PGTC seizures was observed beginning on treatment day 8. The most common adverse event was headache (lamotrigine XR 14%, placebo 16%).

Lacosamide: new adjunctive treatment option for partial-onset seizures

IMPORTANCE OF THE FIELD

Epilepsy is one of the most common neurological disorders, affecting up to 2% of the population worldwide. Studies show that patients with refractory seizures have higher morbidity and mortality rates, as well as a poorer quality of life, than those with controlled seizures. Therefore, treatment that reduces the frequency of seizures may improve patients' quality of life. Lacosamide (LCM) is a recently approved anticonvulsant in Europe and the USA which offers new mechanisms of action and favorable safety profiles. Efficacy data have shown fast onset of anticonvulsant effects and significant reduction of partial-onset seizures as adjunctive therapy at LCM 200 and 400 mg/day, even in a severely refractory population.

AREAS COVERED IN THIS REVIEW

This article reviews three pivotal clinical trials of LCM, including its efficacy and tolerability over 7 years. In addition, LCM's key pharmacodynamics and pharmacokinetics from a search of the literature are reviewed in detail. This article also includes recent publications on the safety and use of intravenous LCM solution for patients with epilepsy.

WHAT THE READER WILL GAIN

This article provides comprehensive review of efficacy and safety information of LCM along with comprehensive pharmacokinetic information, which includes absolute bioavailability, low protein binding, lack of hepatic enzyme induction or inhibition, and low potential for drug-drug interactions.

TAKE HOME MESSAGE

Considering the fact that more than 30% of epilepsy patients remain refractory despite various antiepileptic drugs, LCM may provide added benefit to patients with refractory seizures.

A comparison of pregabalin, lamotrigine, and placebo as adjunctive therapy in patients with refractory partial-onset seizures

PURPOSE

This study assessed the comparative efficacy of pregabalin for refractory partial seizures.

METHODS

Four-hundred and thirty-four patients with partial seizures were randomized to pregabalin, lamotrigine, or placebo as adjunctive therapy for 17 weeks of double-blind treatment. In phase I (11 weeks), pregabalin was titrated over 1 week and lamotrigine over 5 weeks to fixed dosages of 300mg/day for both. In phase II (6 weeks), patients not yet seizure-free were increased to pregabalin 600mg/day or lamotrigine 400mg/day.

RESULTS

During phase I, there was a nonsignificant trend toward a greater reduction in seizures with pregabalin versus placebo and lamotrigine. Across the 17 weeks of treatment, pregabalin showed a median percentage reduction from baseline in seizure frequency of -20.0% (p=.001) versus placebo, and -9.7% (p=.080) versus lamotrigine. The responder rate (> or =50% reduction in seizure frequency) for pregabalin exceeded that of placebo (36% vs 21%; p=.007) and lamotrigine (36% vs 24%; p=.04). Adverse events were consistent with the known safety profiles of pregabalin and lamotrigine.

DISCUSSION

Pregabalin was demonstrated to be noninferior to lamotrigine in the treatment of refractory partial seizures. Overall conclusions were complicated by an unusually large and heterogeneous placebo response.

Seizure aggravation by antiepileptic drugs

Seizure aggravation by antiepileptic drugs (AEDs) is an overestimated phenomenon. While it undoubtedly occurs, the quality of evidence in most published reports is poor. Although seizure aggravation can be examined in clinical trials in the same way as seizure improvement, this is rarely done. Before concluding that an increase in seizures after the introduction of a new drug represents pharmacodynamic aggravation, alternative explanations should be explored. These include spontaneous fluctuation of seizure frequency, the presence of known seizure aggravators (such as sleep deprivation, alcohol, and psychotropic medications), progression of epilepsy, the development of drug resistance, and replacement of a partially effective drug with a less effective drug. The risk of incorrectly blaming a drug for a deterioration in seizures can be minimized by establishing baseline seizure frequency over a period long enough to encompass the extremes of seizure fluctuation and by educating the patient that a temporal relationship may not be a causal relationship. When feasible, the patient should continue the drug long enough to establish if the deterioration is transient. If the drug is stopped, rechallenge should be considered. The risk of seizure aggravation can be minimized by accurate diagnosis of the epilepsy syndrome and appropriate choice of AED.